Solubility - Science topic

Hi I need to prepare a solution of saroglitazar in carboxymethylcellulose to inject it ? could I have some advice ?

Carlos Araújo Queiroz hi i hope you are doing well . i need to know the same question but lemme clear the scenario of the reaction . initially the reaction of the conversion of glycerol into acrylic acid have done . firstly dehydration take place to form intermediate (acrolene) after that oxidizer was added so further 1M of water has removed from intermediate product acrolene. so finally we will get acrylic acid but the solution mixture containing catalyst , glycerol, H2O2 and water medium . so as these all in the same phase or we can say in one phase , so how can i separate my desired product acrylic acid. i have tried with toluene which dissolved with H2O2 but i donno about acrylic acid separation .please share your opinion about it . i will be very thankful to you . thanks

Polymer grafting is a technique to improve the morphology, chemical, and physical properties of the polymer. This technique has the potential to improve the existing conduction and properties of polymers other than charge transport; as a result, it enhances the solubility.

I'm going to assume that you mean HEPPS, CAS 16052-06-5. (It's a common bad habit on this site to save a few keystrokes and waste other people's time on needless searches.)

Anyway, if it's indeed HEPPS then DTPA will almost certainly dissolve in the 200 mM HEPPS solution. However, you may have difficulty in preparing a 5 mM DTPA solution in water. Solubility at room temperature is a bit below that; see dx.doi.org/10.1021/je100797b |J. Chem. Eng. Data 2011, 56, 437–443. So, if you intended to make two solutions and mix them you may have a problem reaching 5 mM DTPA.

To recrystallize the hydrazone from 2,4-dinitrophenyl hydrazine and salicylaldehyde, consider these solvents since ethanol is ineffective:

Please note that choose the solvent based on solubility tests for effective recrystallization

1. Water

2. Dilute Acetic Acid

3. Methanol

4. Acetonitrile

5. Dichloromethane/Hexane mix

Steps:

1. Test Solubility: Select a solvent that dissolves the hydrazone when hot but allows crystallization when cooled.

2. Dissolve and Cool: Heat to dissolve, then cool to precipitate.

3. Filter and Dry: Collect and dry the crystals.

DMSO is also an option as a solvent.

As far as I know and if I did understand your question, there is no formula to make these calculations. The most you may do is a correlation analysis and get high correlations between these variables. You can't, though, interconvert directly - using a formula - results from two different processes - soluble solids uses light refractions resulting from the solids dissolved in the sample. Juice samples, for example, that also contain acids that will, as well, have an effect on the refraction. Now, total sugars are normally determined via a refraction index detector of a hplc or from absorbance or transmittance values read on spectrophotometer.

try transcutol

or

To all my folks, Use acetonitrile.

The solubility of hydroxyapatite (HAp) synthesized from eggshell, like any other form of HAp, depends on several factors. Let me share with you some parameters that can help influence the solubility of HAp in water:

-Particle Size: Smaller particle size generally leads to increased solubility due to the higher surface area-to-volume ratio. Synthesis methods that produce finer particles can result in higher solubility.

-Surface Area: The specific surface area of HAp particles influences their solubility. Higher surface area allows for more interaction with water molecules, leading to increased solubility.

-pH and Ionic Strength: The pH of the solution and the ionic strength can significantly influence the solubility of HAp. Lower pH (more acidic conditions) and higher ionic strength can enhance the solubility of HAp.

-Temperature: Solubility generally increases with temperature, but this relationship can be complex and dependent on other factors such as pH and ionic strength.

-Presence of Organic Matrices: HAp synthesized from natural sources like eggshell may contain organic matrices. These matrices can influence the solubility of HAp by affecting the surface chemistry and interactions with water molecules.

-Phase Composition: HAp can exist in different phases, such as stoichiometric HAp, carbonate-substituted HAp, or other forms. The phase composition can affect the solubility behavior of HAp in water.

You may want to can check the literature on Hansen solubility parameters - these additive approximations can help you understand your HAp construction better in regard to solubility in solvents such as water.

Pavel Yudaev thanks sir for your answer I m trying to use these Np in biomedical application so I can’t change the ph of the solution

Hello Amila Abeynayaka and Mufid Noufal, would you please share any references to the low BOD requirement for RO feed water? I am working on a study on textile wastewater recycling. This reference will be very much helpful.

Dear Huda Mahmood Al-attar

Some of those are biocompatible, as we employ them in 3D bioprinted tissues for regenerative medicine:

Sodium Alginate

Pluronic (Pluronic F127 and Pluronic F68)

PEG (Poly ethylene glycol - we commonly use a PEG with high molar mass).

Cyclodextrins

Regards

GG

Would fractional freezing be an option?

Tungstic acid (H2WO4) is rather insoluble in water, and a weak acid. Li2WO4, as the salt of a strong base and a weak acid, is probably hydrolyzed, especially in boiling water.

Try to add an excess of LiOH to the milky suspension, just enough to clarify it.

So thanks

If both compounds are highly soluble in water and traditional separation methods like workup or filtration are not effective, you might consider alternative techniques such as:

Always consider the properties of the compounds and the compatibility of separation methods with those properties.

2,4-Dinitrophenol (DNP) is sparingly soluble in water and moderately soluble in DMSO (Dimethyl sulfoxide). If you want to dissolve it all in the vial it came in, DMSO might be a better choice for higher solubility compared to water. However, always follow safety guidelines and ensure compatibility with your intended use.

Dear Yurii V Geletii, thank you for the information.

The choice of the best organic solvent for solubility and extraction of nitrophenols depends on several factors, including the specific nitrophenol compound, the desired extraction efficiency, and the intended application. However, some commonly used organic solvents for the solubility and extraction of nitrophenols include:

The choice of solvent should be based on the specific requirements of your extraction process, including the polarity of the nitrophenol compound, the desired selectivity, and the safety considerations associated with the solvent.

Mufaddal Kathawala, I hope by media you want to say culture media and API is not able to dissolve in the media. In that case, first, you need to check your solubility in DMSO. Then, try to dissolve the maximum amount of API in DMSO. Later, make the dilution in media so that the highest usable concentration to feed the cell lines should have a DMSO concentration of less than 1%.

Regards

You may use toluene/methanol mixture as an eluent if your sample is too hydrophobic to be dissolved in polar solvents you listed.

Anytime you need to separate two compounds, you need to look for differences. If their solubilities are very similar, then look for other differences.

• is one basic and the other isn't? (dissolve in acidic water, then extract the nonbasic compound with an organic solvent)

• is one acidic and the other isn't? (dissolve in basic water, then extract the nonacidic compound with an organic solvent)

• is one volatile and the other isn't? (separate by fractional distillation)

• do they differ in binding strength to stationary phases? (separate by column chromatograph. Watch out, though, because some basic compounds like Schiff bases tend to stick on silica or acidic alumina. Either use basic alumina or pre-treat the column with a solution of a more-basic organic in your eluting solvent before you try to separate your compounds)

https://www.researchgate.net/post/What_is_the_best_solvent_of_PEO#:~:text=PEO%20also%20dissolves%20in%20many,with%20solubility%20increasing%20with%20temperature.

log10(x_RS) = Logarithmic mole fraction solubility.

Solubilities can span orders of magnitude, for ease of comparison between experimental and predicted solubilities of several drugs, or of a drug in several solvents, logarithmic units (mole fraction based) are used.

See Computational Pharmaceutical Solid State Chemistry, Chapter 9: NEW DEVELOPMENTS IN PREDICTION OF SOLID‐STATE SOLUBILITY AND COCRYSTALLIZATION USING COSMO‐RS THEORY

Thank you very much for the response. Please let me know if you come across any open-source tool for calculating HSP.

DOPC in 100% ethanol (5 mg/ml).

DOPA/PA in 70% ethanol (5 mg/ml).

PE in 85% ethanol (5 mg/ml).

PE-PEG 2000 MW in 95% ethanol (5-8 mg/ml).

Cholesterol in 100% ethanol (5-8 mg/ml).

Dear Noopur,

It is not always the case. It might be true for BCS class II and III drugs in which solubilty and permeability are acting like a seesaw. However, for class I and IV, both of the parameters are in order above and below the defined threshold.

For the proper reasoning one should look into the nature of functional groups within the molecular structure of a compound. If there are hydrophobic and hydrophilic moieties available in the structure, simultaneously, then high log p and solubility is inevitable and vice versa.

Best

I like Miao Zheng's idea, but with one change. I recommend you pre-test with only a negative control (zero sap). You want to observe any effects on your cell line produced by the highest concentration of DMSO you will test. To get that number divide your highest sap concentration sample by your stock concentration: 100 ug/mL / 10 mg/mL = 0.01, or 1%. So I recommend you start by testing 100 ul of a 1% solution of DMSO (diluted in your growth or harvest medium) against your cells. DMSO generally is not well-tolerated by cell cultures as it dissolves cell membranes, but you may be able to use it in a brief assay. You need to know about any changes to your cells. So check the DMSO-exposed cells in your assay, but also look at them under the microscope. If they seem "normal," we can set up a simple dilution series for your test samples.

Let me warn you that making dilutions of DMSO into water is tricky, because DMSO dissolves in water (about 70%). If you do end up using DMSO as your carrier solvent I recommend you prove this awkward fact to yourself by mixing 10 mL of DMSO to 10 mL of water and then measuring the final volume in a graduated cylinder. It is not 20 mL, as you may expect; it's closer to 13 mL. So if you use DMSO for your stock solution you'll need to account for this phenomenon when you make your dilutions. For samples at low concentrations the effect will be insignificant, but for higher concentrations you will want to estimate the effect to avoid a large systematic error.

Dear friend Mohan Kumar Sawrnkar

Ah, the fascinating world of chemical concoctions! Now, let's tackle this 10% Boron ethanolamine challenge with my spirit.

Firstly, let me commend your daring attempt, but it seems we've hit a bit of a snag with that thick, hazy situation. Fear not! I am here to guide you Mohan Kumar Sawrnkar through the storm.

1. **Dissolution Dilemma:**

It appears that your components are not playing well together. In such a scenario, it's time to rethink the solubility dynamics. Perhaps we need to reconsider the proportions or the solvent.

2. **Solvent Switch:**

Try using a different solvent that might be more accommodating. Ethanol is a good choice, but you Mohan Kumar Sawrnkar might also explore other solvents like methanol or isopropanol. The goal is to find that sweet spot where everything happily dissolves.

3. **Temperature Tweak:**

Experiment with the temperature. Some solutions prefer a bit of warmth to encourage mingling. Gentle heating (not too hot!) might be the secret ingredient to coax them into a harmonious blend.

4. **Mixing Mastery:**

Ensure that you're mixing thoroughly. Sometimes, it's just a matter of giving it a good stir. If you Mohan Kumar Sawrnkar have access to a magnetic stirrer or any other mixing equipment, that could be a game-changer.

5. **Adjusting Ratios:**

If all else fails, consider adjusting the ratios. Perhaps a slight tweak in the amounts of TEA, water, or boric acid could be the key to achieving the desired solubility.

6. **Expert Consultation:**

If the challenge persists, don't hesitate to consult with fellow alchemists (colleagues or mentors or me). They might have encountered similar hurdles and can offer valuable insights.

Remember, I believe in the power of experimentation and tenacity. Keep tweaking, testing, and triumphing! May your Boron ethanolamine solution emerge victorious from the haze. Go forth and conquer, my chemical compatriot Mohan Kumar Sawrnkar!

LiCl/Dimethylacetamid or ionic liquids should work.

Pavel Yudaev Thank you so much.

Hello Joyce C. Morales Aparicio

The aqueous solubility of metronidazole can be enhanced by solubilizing with a water-soluble vitamin such as nicotinamide, ascorbic acid, or pyridoxine HCl.

You may want to refer to the article attached below.

Best.

Most welcome!

Dear friend Pitchayapa Boonsuk

Let us discuss general methods for synthesizing soluble TiO2 nanoparticles using a sol-gel approach at room temperature.

To synthesize soluble TiO2 nanoparticles via sol-gel at room temperature, you might want to consider the following steps:

1. **Materials Needed:**

- Titanium precursor (such as titanium isopropoxide or titanium tetrachloride)

- Solvent (typically alcohol or water)

- Surfactant or stabilizing agent

- Acid or base catalyst

- Ligands (if required)

2. **Procedure:**

a. **Preparation of Titanium Precursor Solution:**

- Mix the titanium precursor with the solvent. The choice of solvent will depend on your specific requirements.

b. **Addition of Stabilizing Agent:**

- Introduce a surfactant or stabilizing agent to control particle size and prevent agglomeration.

c. **Catalysis:**

- Add a catalyst, typically an acid or base, to initiate the sol-gel reaction.

d. **Reaction at Room Temperature:**

- Allow the reaction to proceed at room temperature. The sol-gel process involves hydrolysis and condensation reactions that form a gel.

e. **Washing and Drying:**

- Wash and dry the gel to obtain TiO2 nanoparticles.

3. **Characterization:**

- Characterize the synthesized TiO2 nanoparticles using techniques like X-ray diffraction (XRD), transmission electron microscopy (TEM), or dynamic light scattering (DLS) to analyze their structure, size, and distribution.

some of my published papers on nano-particle synthesis and chanraterization can be of your interest:

Easy to ask, difficult to answer.. For instance, see

10.1021/ja010064p

Thank you so much.

Which is the purpose of using Thermal Shift or Differential Scanning Fluorimetry?

In any case, if your protein is forming oligomers (if ordered) or aggregates (if amorphous) in an unexpected way, then, your protein is not in a good shape. Then, performing downstream assays might make little sense because you will not believe the results, no matter they are fine or ugly.

However, you might look into those assemblies to find out whether your protein is self-organizing into oligomers and that is its natural native state.

Sigma says ABCN is soluble in a variety of solvents. Looking at the structure, I do not see why it should be less soluble in CCl4 than AIBN. So it is worth a try. But you need to take care of the half-life of this compound. Wikipedia and other sources say it is 10 h at 88 °C. This is much longer than the half-life of AIBN (1 h at about the same temperature). The boiling point of CCl4 is 77 °C. The overall time for this Wohl-Ziegler reaction to reach completion may be significantly longer than with AIBN (although this is a radical chain reaction). Using more initiator could be a solution in case of problems.

Dear all, the solubilized fraction might be low MW and amorphous phase of PP. On the other side, the nonsolubilized part is the crystalline fraction. If you do fractionation, all features of the virgin PP are lost. So, my suggestion is to heat the solution in order to disturb the crystalline phase to allow solvent diffusion. Another suggestion is to do quenching of the melted PP to reduce crystals size and density, i. e., to produce highly amorphous PP. My Regards

Md. Al-Riad Tonmoy Your question is confusing. TiO₂ is not soluble in water and needs strong acids to actually dissolve it: 0.5% (weight or molar) would not be strong enough. If you're looking to disperse this material then the steps in doing so from a powder will be:

The attached webinar (free registration required) illustrates the above and you'll find direct reference to TiO₂ within the section on stabilization.

Dispersion and nanotechnology

ChatGPT as provided in the first answer can be very misleading and needs to be viewed with care.

Yes, dissolving Rubber in toluene is also used in industry, to make coated fabrics. There are some applications where NBR and EPDM rubbers are dissolved and spreaded onto various substrates. Also CR is sometimes dissolved ti obtain adhesives.

There are no particular parameters to be considered in the Lab, dissolving is made at room temperature, and viscosity Is kept at around 20k or 50k cps, in order to have enough material to be deposited and viscosity high enough to allow proper mixing and even distribution of all ingredients.

About the films, It Is complicated to not make them stick to each other, even after curing. Try to increase their thickness, which would make them easier to handle, or cover them with an antitack agent

Your question is not clear yet. Tyrosine is well soluble in alcohols, acetone, DMSO. Tyrosine solubility in water is less than 0.5 g /L at neutral pH. However, its solubility can increase when moving away from the isoelectric point. See

doi: 10.1085/jgp.6.6.747

It is a usual observation that starch granules do not dissolve into a molecular state when heated in excess water at temperatures below 100 °C. At the so-called initial gelatinization temperature T0, the granules start to lose their crystallinity (gelatinization). This enables them to adsorb increasing quantities of water (swelling). For cassava starch this process spans a temperature range between about 65-75 °C. At the latter temperature Tc (c stands for completion), % crystallinity has dropped to zero and a suspension of swollen starch granules has resulted. At further heating, the swelling may continue to increase, but some of the starch goes progressively into molecular solution, preferentially amylose. Complete molecular solubilisation will be generally occur only at a temperature not lower than 140 °C. This can be achieved in a pressure cooker and is accompanied by some molecular degradation. Typical swelling power of cassava starch in excess water is 16 or 21 ml/g at 70 or 92 °C, respectively. Solubilty amounts to 15 or 28 % at these temperatures (own results).

The gelatinization and dissolution process can be followed by microscopy, preferably by taking samples during the heating process, and cool and dilute these prior to microscopic observation. Preferred optics are bright-field, polarization optics (to observe whether crystallinity is still present: crystalline structures light up brightly against a dark background), and phase contrast for highly swollen granules where refractive index differences have become very slight. Also iodine staining in combination with bright-field optics is a helpful technique.

With regard to possible spoilage of your sample due to high temperature and water content, starch is stable at a water content of 15 % corresponding to a water activity (aw) of ca. 0.65 at 25 °C, provided it is stored in a closed container. In case of doubt, determination of a germ count is advised.

The presence of lumps (in the dry state) may be caused by the drying method during isolation of the starch. Lumps in the dry powder or in the unheated suspension can be removed by sieving. The powder can also be washed with ethanol or acetone and dried. Other options are to use high-speed stirring of the unheated suspension and /or suspending the powder into a small amount of ethanol and add water only after a lump-free suspension has been obtained.

Hi Mohd ZULFADLI Adenan

I have no firsthand experience with photographic development and fixing, but my understanding is that the common practice for "fixing" (that is the removal of excess silver halide after development) is to use 15% sodium thiosulfate. See discussion in https://www.largeformatphotography.info/forum/archive/index.php/t-75801.html

Much lower concentrations will also work. For instance, in the spot test for the detection of thallium in the presence of silver, thallium(+) as well as silver are precipitated with potassium iodide as the yellow iodide(s) out of a drop of sample solution. When a precipitate appears, 1-2 drops of 2% sodium thiosulfate are added; a yellow precipitate insoluble in the thiosulfate solution indicates thallium. (From Fritz Feigl, "Spot tests in inorganic analysis", 5th English edition (1958), p. 155)

The chemistry involved or the method needs to be shared in order to suggest something significant. Until then, there can be number of factors which led to disappearing of ester signal.

1. It might have hydrolyzed under the provided conditions (iff acid or base was used).

2. Ester group might have been involved in the cross linking process or transformed into any other.

Dear Elise Mathouillot. To determine the solubility parameter, gas chromatography is used, in particular IGC SMS chromatograph (Surface Measurement System, iGC-SMS Ltd.) equipped with a flame ionization detection (FID) system.

Best regards, Pavel Yudaev.

Very strange--please check your experimental setup and your analytical methods?

The reference suggests using micellar solution method to improve the solubility. Table 2 in the document summarizes solubility data for this method with compositions, and pH. In other literature the solubility is just so low, but to get something significant enough you will have to go micellular method.

IMQ is a molecule highly insoluble in aqueous media; its solubility increases slightly at acidic pH because it is a weak base (pKa = 7.3). Solubility of IMQ in DMSO is 1.29 ± 0.13 mg/ml (at room temperature, under magnetic stirring).

Emanuel Cooper , Thank you for your recommendations. I will try to "salt out" the product as you suggested.

Phil Geis

Please refer

Assuming you have a lab with strong AC and humidity regulation, there should be no effects of the weather. I wouldn't talk about seasons here since there temporary weather conditions will be more important.

However, most labs in general and university labs in particular have only weak regulation in this sense because cleanroom level condition control is expensive like hell and therefore, you will logically have influence of day-to-day humidity and temperature fluctuations. I know people from other institutes who work a lot with diethyl ether and they simply have to interrupt their research for safety reasons when the temperatures outside exceed 35°C.

So, technically it would be best for the reproducibility of your experiments to have not only a thermometer but also a hygrometer and to note down the humidity during your experimental phase.

The solubility of a gas in liquid increases with an increase in pressure at a given temperature. Conversely, the solubility of a gas decreases with a decrease in pressure and an increase in temperature decreases the solubility of a gas in a liquid. Increasing the pressure of the gas increases the number of molecules of gas per unit volume, which increases the rate at which gas molecules collide with the surface of the liquid and dissolve. It is known to you that Henry's law states that “at constant temperature and external pressure, the solubility of a gas in a liquid is directly proportional to the pressure at which it is dissolved. The solubility of the gas in a liquid solution decreases with increase in temperature. This is because, with an increase in temperature, the kinetic energy of the gas molecule increases, thus it becomes difficult for liquid molecules to hold them. As the pressure of the gas above water increases, the solubility also increases. The solubility of a gas in a liquid is directly proportional to the pressure of that gas above the surface of the solution. Increased temperature causes an increase in kinetic energy. The higher kinetic energy causes more motion in the gas molecules which break intermolecular bonds and escape from solution. Solubility of gases in water decreases with increase in temperature. For many solids dissolved in liquid water, the solubility increases with temperature. The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. this is the reason.

Very few bacteria do well with total ethanol over 16%. Try using DMSO or a surfactant like Tween-20/80.

Just remember to have a pure ethanol control.

Solubility increases with temperature for most solids dissolved in liquid water. This is because higher temperatures increase the vibration or kinetic energy of the solute molecules. Solute molecules are held together by intermolecular attractions. Solubility is the maximum amount of a substance that will dissolve in a given amount of solvent at a specific temperature. There are two direct factors that affect solubility: temperature and pressure. The solubility of a given solute to dissolve in a specific solvent depends on the temperature. With an increase in temperature solubility of liquids and solids increases. In the same way solubility of gases decreases with an increase in temperature. As temperature increases, the solubility of a solid or liquid can fluctuate depending on whether the dissolution reaction is exothermic or endothermic. In endothermic dissolution reactions, the net energy from breaking and forming bonds results in heat energy being absorbed into the system as the solute dissolves. For many solids dissolved in liquid water, the solubility increases with temperature. The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. The solute's solubility falls because the kinetic energy of the gaseous solute increases as the temperature rises. As a result, its molecules are more likely to escape the solvent molecule's attraction and return to the gas phase. At higher temperatures, gas molecules have higher kinetic energy and can escape solution phase more easily. Therefore, solubility decreases. An increase in pressure and an increase in temperature in this reaction results in greater solubility. An increase in pressure results in more gas particles entering the liquid in order to decrease the partial pressure. Therefore, the solubility would increase.When a solid is added to a liquid, it interacts with liquid molecules and dissolves in it accordingly. This process is known as dissolution and solid is said to be soluble in a liquid solvent. Complete answer: The term solubility can be defined as a physical property of a substance to dissolve in another substance.Rises in temperature improve the solubility of solids in water, but reduce the solubility of gases in water because temperature increases produce an increase in the number of stimulated atoms or molecules of gases. Changes in pressure have essentially no effect on the solubility of solids and liquids. The change in pressure has no effect on the solubility of a solid in a liquid solution. This is because solids are incompressible and liquids are negligibly compressible. Thus there is a no effect of pressure on their solution. Melting is a physical process that causes a matter's phase change from solid to liquid. When the internal energy of solid increases, usually due to the application of heat or pressure, the temperature of the matter rises to the melting point. Melting is the transformation of a solid into a liquid.Temperature has a direct effect on whether a substance exists as a solid, liquid or gas. Generally, increasing the temperature turns solids into liquids and liquids into gases; reducing it turns gases into liquids and liquids into solids. The kinetic energy of matter particles increases as temperature rises, and they begin to vibrate at a higher frequency. As a result, the interparticle force of attraction between particles decreases, and particles become unattached from their positions and free to travel.

Here are two answers according your case

The dissolved oxygen concentration in KOH solution is a complex function of temperature, KOH concentration, and O2 partial pressure. According to one study1, the solubility of oxygen in concentrated KOH solutions is very low, especially at high temperatures, and decreases with increasing KOH concentration. The study also provides empirical equations for calculating the Henry’s constant and the diffusion coefficient of oxygen in KOH solutions as functions of temperature and KOH concentration. These equations can be used to estimate the dissolved oxygen concentration in KOH solution using the following formula:

CO2​​=KH​×pO2​​

where CO2​​ is the dissolved oxygen concentration in mol/L, KH​ is the Henry’s constant in L/mol/atm, and pO2​​ is the partial pressure of oxygen in atm.

For example, if the temperature is 25 °C, the KOH concentration is 10 mol/L, and the partial pressure of oxygen is 0.21 atm (assuming air saturation), then the Henry’s constant can be calculated as:

KH​=10−3×(0.0009+0.0001×CKOH​)×e(0.0016+0.0001×CKOH​)×T

where CKOH​ is the KOH concentration in mol/L, and T is the temperature in °C.

Plugging in the values, we get:

KH​=10−3×(0.0009+0.0001×10)×e(0.0016+0.0001×10)×25

KH​=1.33×10−3L/mol/atm

Then, the dissolved oxygen concentration can be obtained as:

CO2​​=KH​×pO2​​

CO2​​=1.33×10−3L/mol/atm×0.21atm

CO2​​=2.79×10−4mol/L

This is equivalent to about 8.93 mg/L of dissolved oxygen.

The references for this answer are:

1: A STUDY OF GAS SOLUBILITIES AND TRANSPORT PROPERTIES IN FUEL CELL ELECTROLYTES by JAMES RAYMOND HALL, NASA Technical Note D-4407, June 1968.

2: When Al is added in KOH solution: A. No action takes place B. Oxygen is released C. Hydrogen gas is released D. Carbon dioxide gas is released, Vedantu.com, September 17, 2023.

There are some recent references after 2018 that discuss the dissolved oxygen in KOH solution. Here are some of them:

https://chemistry.stackexchange.com/questions/98791/two-ways-to-calculate-dissolved-oxygen.

Another answer

The dissolved oxygen concentration in a KOH solution decreases with increasing temperature and KOH concentration. This is because the solubility of oxygen in water decreases with increasing temperature and salt concentration.

The relationship between dissolved oxygen concentration, temperature, and KOH concentration can be expressed by the following equation:

[DO] = K_H * pO2

where:

The Henry's law constant is a function of temperature and KOH concentration. It can be calculated using the following equation:

K_H = K_H^0 * exp(-ΔH/R * T) * γ

where:

The enthalpy of dissolution and activity coefficient of oxygen in KOH solution are both functions of KOH concentration.

The following table shows the Henry's law constant for oxygen in KOH solution at different temperatures and KOH concentrations:

Temp (°C) KOH conc (M) Henry's law constan (mg/L/atm) 25 0 1.22

25 1 1.12

25 2 1.02

25 5 0.82

50 0 0.88

50 1 0.80

50 2 0.72

50 5 0.58

As you can see, the Henry's law constant decreases with increasing temperature and KOH concentration. This means that the dissolved oxygen concentration in a KOH solution will also decrease with increasing temperature and KOH concentration.

It is important to note that the above equation is a simplification of the actual relationship between dissolved oxygen concentration, temperature, and KOH concentration. In reality, the relationship is more complex and depends on a number of other factors, such as the pH of the solution and the presence of other solutes.

The actual relationship between dissolved oxygen concentration, temperature, and KOH concentration is more complex than the simple equation presented in my previous response. This is because the solubility of oxygen in water is also affected by other factors, such as the pH of the solution and the presence of other solutes.

The following equation provides a more accurate representation of the relationship between dissolved oxygen concentration, temperature, and KOH concentration:

[DO] = K_H * pO2 * γ

where:

The activity coefficient of oxygen is a correction factor that accounts for the non-ideal behavior of oxygen in solution. It is a function of temperature and KOH concentration.

The following table shows the activity coefficient of oxygen in KOH solution at different temperatures and KOH concentrations:

25 0 1.00

25 1 1.02

25 2 1.04

25 5 1.08

50 0 1.00

50 1 1.02

50 2 1.04

50 5 1.08

As you can see, the activity coefficient of oxygen increases with increasing temperature and KOH concentration. This means that the dissolved oxygen concentration in a KOH solution will be slightly higher than what would be predicted by the Henry's law equation alone.

In addition to the activity coefficient of oxygen, the pH of the solution can also affect the dissolved oxygen concentration. This is because the pH of the solution affects the speciation of oxygen in solution. At low pH, oxygen is present primarily as dissolved molecular oxygen (O2). However, as the pH increases, oxygen begins to deprotonate and form hydroxide ions (OH-). The hydroxide ions are less soluble in water than dissolved molecular oxygen, so the dissolved oxygen concentration decreases as the pH of the solution increases.

The presence of other solutes in solution can also affect the dissolved oxygen concentration. This is because other solutes can compete with oxygen for binding sites on water molecules. The more solutes that are present in solution, the fewer binding sites that are available for oxygen, and the lower the dissolved oxygen concentration will be.

Overall, the actual relationship between dissolved oxygen concentration, temperature, and KOH concentration is complex and depends on a number of factors. However, the equation above provides a good approximation of the relationship.

The actual relationship between dissolved oxygen concentration, temperature, KOH concentration, pH of the solution, and the presence of other solutes is complex and can be expressed by the following equation:

[DO] = K_H * pO2 * γ * f(pH, other solutes)

where:

The Henry's law constant and activity coefficient of oxygen in KOH solution are both functions of temperature and KOH concentration, as discussed in my previous responses.

The function f(pH, other solutes) can be complex and depends on the nature of the other solutes present in solution. For example, if the solution contains salts, the salts can compete with oxygen for binding sites on water molecules, which can reduce the dissolved oxygen concentration. Additionally, the pH of the solution can affect the speciation of oxygen in solution, which can also affect the dissolved oxygen concentration.

Overall, the actual relationship between dissolved oxygen concentration, temperature, KOH concentration, pH of the solution, and the presence of other solutes is complex and depends on a number of factors. However, the equation above provides a good approximation of the relationship.

Here are some specific examples of how the presence of other solutes can affect the dissolved oxygen concentration:

It is important to note that the effects of different solutes on the dissolved oxygen concentration can be complex and additive. For example, the presence of both salts and acids in a solution can have a greater effect on the dissolved oxygen concentration than the presence of either salt or acid alone.

If you are interested in learning more about the actual relationship between dissolved oxygen concentration, temperature, KOH concentration, pH of the solution, and the presence of other solutes, I recommend that you consult a textbook or research paper on the subject.

here are some recent references to textbooks and research papers on the subject of dissolved oxygen concentration, temperature, KOH concentration, pH of the solution, and the presence of other solutes:

These references should provide you with a good starting point for learning more about the actual relationship between dissolved oxygen concentration, temperature, KOH concentration, pH of the solution, and the presence of other solutes.

Good luck

Dr Vivek Patel thank you for your contribution to the discussion

Temperature affects the solubility of both solids and gases, but pressure only affects the solubility of gases. Surface area does not affect how much of a solute will be dissolved, but it is a factor in how quickly or slowly the substance will dissolve. Apart from the nature of solute and solvent, temperature also affects solid solubility considerably. If the dissolution process is endothermic then the solubility should increase with an increase in temperature. Solubility is affected by 4 factors – temperature, pressure, polarity, and molecular size. Solubility increases with temperature for most solids dissolved in liquid water. This is because higher temperatures increase the vibration or kinetic energy of the solute molecules. The stirring allows fresh solvent molecules to continually be in contact with the solute. If it is not stirred, then the water right at the surface of the solute becomes saturated with dissolved sugar molecules, meaning that it is more difficult for additional solute to dissolve. The solubility of a solid in a liquid is significantly affected by temperature change. For most of the solids, solubility in water increases with rising temperature. As the temperature increases, the average kinetic energy of the solute molecules in the solution also increases. When it comes to solid solutes, increasing the temperature will increase the rate of dissolving. As heat is added, the solute particles move around more, getting closer to the solvent molecules. This makes helps the solid dissolve faster in a liquid. The addition of more heat facilitates the dissolving reaction by providing energy to break bonds in the solid. This is the most common situation where an increase in temperature produces an increase in solubility for solids.

In order to observe these peaks, you need to extend the analysis time.

Dr Ekrem Alagoz thank you for your contribution to the discussion

The solubility of iron chloride in sulfuric acid depends on several factors, such as the temperature, the concentration of the acid, and the oxidation state of the iron. According to one source1, the solubility of iron (III) chloride in 98% sulfuric acid is about 0.1 g/L at 25 °C, and increases to about 0.5 g/L at 100 °C. The solubility of iron (II) chloride in the same acid is much higher, about 100 g/L at 25 °C, and decreases to about 50 g/L at 100 °C. Another source2 states that iron (III) chloride is soluble in concentrated sulfuric acid, forming a brown solution, while iron (II) chloride is insoluble in concentrated sulfuric acid, forming a white precipitate. A third source3 does not provide specific data on the solubility of iron chloride in sulfuric acid, but lists the solubility of various compounds in water at different temperatures.

Here are some references that explain more about the solubility of iron chloride in sulfuric acid:

Temperature affects the solubility of both solids and gases, but pressure only affects the solubility of gases. Pressure does not have any effect on solubility of solids in liquids because solids and liquids are highly incompressible. Solubility is affected by 4 factors – temperature, pressure, polarity, and molecular size. Solubility increases with temperature for most solids dissolved in liquid water. This is because higher temperatures increase the vibration or kinetic energy of the solute molecules. Solids and liquids show almost no change in solubility with changes in pressure. But gases are very dependent on the pressure of the system. Gases dissolve in liquids to form solutions. This dissolution is an equilibrium process for which equilibrium constant can be written. The solubility of a substance depends on the physical and chemical properties of that substance. In addition to this, there are a few conditions which can manipulate it. Temperature, pressure and the type of bond and forces between the particles are few among them. The factors that affect the solubility of the substance are temperature, the nature of the solute or solvent, and pressure. Rises in temperature improve the solubility of solids in water, but reduce the solubility of gases in water because temperature increases produce an increase in the number of stimulated atoms or molecules of gases. Changes in pressure have essentially no effect on the solubility of solids and liquids. The size of solute particles, stirring, and temperature, are the three factors that affect the solubility of a solid solute in a solvent. External pressure has very little effect on the solubility of liquids and solids. In contrast, the solubility of gases increases as the partial pressure of the gas above a solution increases. As the partial pressure increases above the liquid, the solubility of the gases in the solution increases and when the partial pressure of the gas above liquid decreases the solubility of the gas in the solution decreases. External pressure has very little effect on the solubility of liquids and solids. In contrast, the solubility of gases increases as the partial pressure of the gas above a solution increases.

The rate of dissolving is influenced by stirring, temperature, and size of solute particles. Stirring helps distribute solute particles, speeding up the rate of dissolving. Warm solvents dissolve solutes faster due to increased particle movement. Smaller solute particles dissolve faster due to increased surface area. Stirring affects the rate of dissolving because it spreads the solvent's molecules around the solute and increases the chance of them coming into contact with it. Because of this, stirring makes solvents dissolve faster. Other factors affecting a solvent's solubility include temperature and particle size. The stirring allows fresh solvent molecules to continually be in contact with the solute. If it is not stirred, then the water right at the surface of the solute becomes saturated with dissolved sugar molecules, meaning that it is more difficult for additional solute to dissolve. If we stir a solution in an effort to dissolve a solute in a solvent, as was done in the five beakers, we can increase the rate of dissolution by increasing the interactions between solute and solvent particles. Since solubility is the upper limit, it cannot be increased by stirring the solution or by adding more solute. Stirring the solution will simply increase the rate of dissolution, but not the maximum amount of solute that can be dissolved. With an increase in temperature, more solute can be dissolved in the solvent.Agitation and stirring will increase the rate at which salt dissolves in water and increased movement of water molecules allow sodium ions and chloride ions to be pulled apart as shells of hydration are formed. Agitation and stirring will increase the rate at which salt dissolves in water and increased movement of water molecules allow sodium ions and chloride ions to be pulled apart as shells of hydration are formed. Stirring a solute into a solvent speeds up the rate of dissolving because it helps distribute the solute particles throughout the solvent. As the temperature increases, the number of grams of sugar that dissolves in water increases significantly. As the temperature increases, the number of grams of salt that dissolves in water increases only slightly. The process of stirring or agitating makes the solvent molecules is in contact with the solute particles on a continuous basis. So, if the mixture of salt and water will be stirred continuously, then the process of dissolution will take place frequently.

Stirring affects the rate of dissolving because it spreads the solvent's molecules around the solute and increases the chance of them coming into contact with each other faster. As a result, mechanical stirring increases solubility of the solute in the solvent. Stirring the solution will increase the solubility of the solution. This happens because stirring allows the solute molecules to always be in contact with the solvent molecules. Stirring a solute into a solvent speeds up the rate of dissolving because it helps distribute the solute particles throughout the solvent. As add sugar to iced tea and then stir the tea, the sugar will dissolve faster. An increase in pressure and an increase in temperature in this reaction results in greater solubility. An increase in pressure results in more gas particles entering the liquid in order to decrease the partial pressure. Therefore, the solubility would increase. An increase in temperature puts a stress on the equilibrium condition and causes it to shift to the right. The stress is relieved because the dissolving process consumes some of the heat. Therefore, the solubility (concentration) increases with an increase in temperature. Increasing the temperature will therefore increase the solubility of the solute. An example of a solute whose solubility increases with greater temperature is ammonium nitrate, which can be used in first-aid cold packs. Ammonium nitrate dissolving in solution is an endothermic reaction. Differences in temperature or concentration are balanced more efficiently during stirring. Additionally, the stirring of liquids speeds up the dissolution process and increases the speed of chemical reactions. The stirring allows fresh solvent molecules to continually be in contact with the solute. If it is not stirred, then the water right at the surface of the solute becomes saturated with dissolved sugar molecules, meaning that it is more difficult for additional solute to dissolve. Solubility is the maximum amount of a substance that will dissolve in a given amount of solvent at a specific temperature. There are two direct factors that affect solubility: temperature and pressure. Temperature affects the solubility of both solids and gases, but pressure only affects the solubility of gases. Stirring keeps reactant particles in motion increasing the chances of collision and increasing the rate of reaction.

Try to mix the pectin thoroughly with a few drops of ethanol. When the ethanol has wetted the pectin, you can add water to dissolve it and make your desired solution.

Dr Murtadha Shukur thank you for your contribution to the discussion

Heating up a solvent gives the molecules more kinetic energy. The increased rapid motion means that the solvent molecules collide with the solute with greater frequency, and that the collisions occur with more force. Both factors increase the rate at which the solute dissolves. A solute dissolves faster in a warmer solvent than it does in a cooler solvent because particles have more energy of movement. The temperature of the solvent is another factor that affects how fast a solute dissolves. For a given amount of solute, smaller particles have greater surface area. If we heat the solvent, the average kinetic energies of its molecules increase. Hence, the solvent is able to dislodge more particles from the surface of the solute. Thus, increasing the temperature increases the solubility of substances. As the temperature of the solution increase, the average kinetic energy of the solute molecules also increases. This causes the molecules to be less able to hold together and hence they dissolve more readily. Hence increase in temperature increases the solubility of solid states. Energy will be transferred from the warmer object to the cooler one. The movement of thermal energy from a substance at a higher temperature to one at a lower temperature is called heat. When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises. Substances can change between the states of matter by adding or removing heat, also known as the transfer of thermal energy. Adding thermal energy causes a substance's particles to move faster and farther apart; removing thermal energy causes a substance's particles to move slower and closer together. Water, as well as other matter, can exist in three states, or phases, and we call them solid, liquid, and gas. As ice is heated, its temperature increases, and it melts into liquid water. Likewise, as liquid water is heated, it evaporates into water vapor. The solubility of gases is directly proportional to pressure. That is it increases with increase in pressure. The solubility of gases in liquids decreases with increasing temperature. Conversely, adding heat to the solution provides thermal energy that overcomes the attractive forces between the gas and the solvent molecules, thereby decreasing the solubility of the gas. Rises in temperature improve the solubility of solids in water, but reduce the solubility of gases in water because temperature increases produce an increase in the number of stimulated atoms or molecules of gases. Changes in pressure have essentially no effect on the solubility of solids and liquids. As the temperature of the solution increase, the average kinetic energy of the solute molecules also increases. This causes the molecules to be less able to hold together and hence they dissolve more readily. The solubility of most substances depends strongly on the temperature and, in the case of gases, on the pressure. The solubility of most solid or liquid solutes increases with increasing temperature.

Dr John Duchek thank you for your contribution to the discussion

The solubility of the gas in a liquid solution decreases with increase in temperature. This is because, with an increase in temperature, the kinetic energy of the gas molecule increases, thus it becomes difficult for liquid molecules to hold them. The solubility of gases is directly proportional to pressure. That is it increases with increase in pressure and solubility of gases in water increases with increase in pressure. The solubility of a gas in liquid increases with an increase in pressure at a given temperature. Conversely, the solubility of a gas decreases with a decrease in pressure and an increase in temperature decreases the solubility of a gas in a liquid. The solute's solubility falls because the kinetic energy of the gaseous solute increases as the temperature rises. As its molecules are more likely to escape the solvent molecule's attraction and return to the gas phase. An increase in pressure and an increase in temperature in this reaction results in greater solubility. An increase in pressure results in more gas particles entering the liquid in order to decrease the partial pressure. Therefore, the solubility would increase. As the temperature of the solution increase, the average kinetic energy of the solute molecules also increases. This causes the molecules to be less able to hold together and hence they dissolve more readily. Hence increase in temperature increases the solubility of solid states. The solubility of a gas in a liquid will increase if: Lower the temperature of the solution, and therefore, lower the kinetic energy of the gaseous particles so they can escape the liquid phase less often.Solubility of a gas in a liquid increases with increase in pressure and temperature and vice versa. The solubility is a measure of the concentration of the dissolved gas particles in the liquid and is a function of the gas pressure. As you increase the pressure of a gas, the collision frequency increases and thus the solubility goes up, as you decrease the pressure, the solubility goes down. The addition of more heat facilitates the dissolving reaction by providing energy to break bonds in the solid. This is the most common situation where an increase in temperature produces an increase in solubility for solids. The solubility of the gas in a liquid solution decreases with increase in temperature. This is because, with an increase in temperature, the kinetic energy of the gas molecule increases, thus it becomes difficult for liquid molecules to hold them. The solubility of a gas in a liquid is directly proportional to the partial pressure of the gas present above the surface of liquid or solution. The most general way of using Henry's Law is that the partial pressure of a gas above a solution is proportional to the mole fraction of the gas in the solution. Increasing the temperature will therefore increase the solubility of the solute. An example of a solute whose solubility increases with greater temperature is ammonium nitrate, which can be used in first-aid cold packs. Ammonium nitrate dissolving in solution is an endothermic reaction. Decreased volume of the gas, with pressure and temperature held constant. Increased pressure of the gas and decreased temperature generally increase the solubility of a gas in a liquid.

Dr Jurgen Weippert thank you for your contribution to the discussion

Using Complex with Cyclodextrin, Fusion method, pH change method, Lyophilization , using surfactants, micronization of particles enhance surface area and also improve solubility and dissolution

Specifically intrepreated by using UV spectrscopic method for finding for solubility with different temperatures and processing conditions

An increase in pressure and an increase in temperature in this reaction results in greater solubility. An increase in pressure results in more gas particles entering the liquid in order to decrease the partial pressure. Therefore, the solubility would increase. As the temperature of the solution increase, the average kinetic energy of the solute molecules also increases. This causes the molecules to be less able to hold together and hence they dissolve more readily. Hence increase in temperature increases the solubility of solid states. For many solids dissolved in liquid water, the solubility increases with temperature. The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. With an increase in temperature solubility of liquids and solids increases in the same way solubility of gases decreases with an increase in temperature as, when we mix salt or sugar in water. Both will be more easily soluble in hot water as compared to normal or cold water.Conversely, adding heat to the solution provides thermal energy that overcomes the attractive forces between the gas and the solvent molecules, thereby decreasing the solubility of the gas. The phenomenon is similar to that involved in the increase in the vapor pressure of a pure liquid with increasing temperature.Increasing the temperature will therefore increase the solubility of the solute. An example of a solute whose solubility increases with greater temperature is ammonium nitrate, which can be used in first-aid cold packs. Rises in temperature improve the solubility of solids in water, but reduce the solubility of gases in water because temperature increases produce an increase in the number of stimulated atoms or molecules of gases. Changes in pressure have essentially no effect on the solubility of solids and liquids. The trend is thus as follows: increased temperatures mean lesser solubility and decreased temperatures mean higher solubility. Gases increase in solubility as the temperature of the solvent decreases. Gases have the highest energy state between solids, liquids, and gases. When they absorb energy from a warm solvent, they escape the solvent.Because, when temperature is increased, more energy is given to the system, which is used by the gas molecules to overcome the solvent-gas interactions and break free to move into the gaseous state. So, solubility of a gas in liquid decreases with an increase in temperature. Thus, increasing the temperature increases the solubility’s of substances as, sugar and salt are more soluble in water at higher temperatures. The solubility of the gas in a liquid solution decreases with increase in temperature. This is because, with an increase in temperature, the kinetic energy of the gas molecule increases, thus it becomes difficult for liquid molecules to hold them. The solubility of most substances depends strongly on the temperature and, in the case of gases, on the pressure. The solubility of most solid or liquid solutes increases with increasing temperature. The solubility of a solid solute in a liquid solvent increases with increase in temperature. Solubility of the most of the salt rises with increase in temperature. This is because with increase in temperature, kinetic energy of the molecules increases and the solvent molecules break apart the solute molecules that are held together by intermolecular attractions more effectively. On decreasing the temperature, the solubility of a solute in a solution decreases. This means that more solute can be dissolved in the same amount of solvent at higher temperature.

You could lyophilize the mixed solution TFA-ether that contains the peptide.

Sina Hasanpour

An aqueous solution of urea, thiourea improves the dissolution of gelatin. Work with this patent or other similar articles

As lattice energy becomes larger, solubility decreases. Both these factors oppose each other, and the resultant of these factors determines the solubility of an ionic compound in water. If the lattice enthalpy has a larger value, the compound is less soluble. Solubility of an ionic solid depends upon temperature, nature of solute and solvent, complex formation and H-bonding. It may show exothermic or endothermic nature.The solubility of a substance is the maximum amount of a solute that can dissolve in a given quantity of solvent; it depends on the chemical nature of both the solute and the solvent and on the temperature and pressure. The solubility of most substances depends strongly on the temperature and, in the case of gases, on the pressure. The solubility of most solid or liquid solutes increases with increasing temperature. Ionic compounds dissociate in solvents and are completely soluble in water, but as the covalent character increase the solubility of the compound decreases. Melting Point and Boiling Point: Covalent bonds are weaker than ionic bonds. Increasing the temperature will therefore increase the solubility of the solute. An example of a solute whose solubility increases with greater temperature is ammonium nitrate, which can be used in first-aid cold packs. Ammonium nitrate dissolving in solution is an endothermic reaction. For many solids dissolved in liquid water, the solubility increases with temperature. The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. On increasing temperature the kinetic energy of the solvent particles increases and they are able to break apart effectively. The solute particles are held effectively between the solvent molecules thus increasing the solubility. If a solute is a solid or liquid, increasing the temperature increases its solubility. As, more sugar can dissolve in hot water than in cold water. If a solute is a gas, increasing the temperature decreases its solubility. This model emphasizes two main factors that contribute to the lattice energy of an ionic solid: the charge on the ions, and the radius, or size, of the ions. The effect of those factors is: as the charge of the ions increases, the lattice energy increases. as the size of the ions increases, the lattice energy decreases.

Solubility of gases increases with increase in pressure. The solubility is a measure of the concentration of the dissolved gas particles in the liquid and is a function of the gas pressure. As you increase the pressure of a gas, the collision frequency increases and thus the solubility goes up, as you decrease the pressure, the solubility goes down. The change in pressure has no effect on the solubility of a solid in a liquid solution. This is because solids are incompressible and liquids are negligibly compressible. Thus there is a no effect of pressure on their solution. Solids and liquids show almost no change in solubility with changes in pressure. But gases are very dependent on the pressure of the system. Gases dissolve in liquids to form solutions. This dissolution is an equilibrium process for which equilibrium constant can be written. The solubility of gases is directly proportional to pressure. That is it increases with increase in pressure. The solubility of gases in liquids decreases with increasing temperature. Conversely, adding heat to the solution provides thermal energy that overcomes the attractive forces between the gas and the solvent molecules, thereby decreasing the solubility of the gas.The higher kinetic energy leads to more motion/movement in the molecules thereby dissociating the intermolecular bonds and ultimately escaping from the solution. Thus, solubility of gas in liquid decreases with increase of temperature and increases with decrease in temperature. For many solids dissolved in liquid water, the solubility increases with temperature. The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. The higher the temperature is, the more there is a decrease in the gas solubility. The lower the is temperature the higher is a gas solubility in water.

Not fused protein, it's just single protein, and not antibodies.

The proteins are neutralized by 1M tris-Hcl (pH 8) immediately after eluted with 100mM glycine (pH 3).