Propylene Glycol - Science topic

I purified one protein using 3 different columns. The last column I used is Butyl 650M hydrophobic interaction column and I eluted my target protein with 50% propylene glycol. I need to remove propylene glycol and concentrate my elution. I tried to remove it with acetone precipitation, and methanol chloroform precipitation. However, both of them resulted in a significant loss of my protein.

I wonder If I can use dialysis or not...due to its water-absorbing characteristic...

I do not want to add additional steps like gel filtration chromatography...

Does anyone have any technical suggestions and ideas?

Hello,

In the video you can see a drying process of the freshly printed thin layer of the ink, 10x10 mm.

Do you know any work dedicated to the mechanism of such drying procesess? What shape can be layer made with a solid content of the ink?

The ink consists of 2 mass parts of 1,2-propanediol and 8 parts of 1-pentanol and a small percent of a PEIE polymer. The substrate is a glass cover with a oxygen plasma treated ITO.

Tom

I want to estimate freezing point of a mixture made from Ehhanol (H₃CCH₂OH, MW: 46.07 g/mol) , mono propylene glycol (CH₃CH(OH)CH₂OH, MW: 76.1 g/mol) and water. And the ratio of the mixure will vary for example I can start with 1:1:1 and so on. I spent couple of week to google it but not able to figure out how to do that. If someone here have some experience with it or have some suggestion / literature then please help to solve for this problem.

I have developed a syrup at pH 3 of a BCS class II molecule using propylene glycol, beta Cyclodextrin, citric acid, antimicrobial preservative, and sweeting agent. But i every time get precipitation after holding 2 to 3 days. When shake the bottle i found smoke like floating of these precipitation. How can I fix the problem. I am looking forward to your help.

I am optimizing the method of developing natural deep eutectic solvent by using different methods, molar ratio and water content. For heating and stirring method, I used 1:1 Choline chloride:1,2 propanediol. The combination does not form liquid either direct heating or in water bath up-to 2 hours. The temperature is below 100 degree C. I tried to add minimal amount of water (less than 50%). However, the combination does not form homogeneous solution. It only form clear homogeneous solution when I put more water (160%) and its stable at room temperature. My concern is some journals mention the excessive water content may disturb the hydrogen bonds between Choline chloride and 1,2 propanediol. I tried to rotavap to remove water content and it starts recrystallising again. I repeated the experiment by using total dried Choline chloride (freeze dried) after reading some suggestions from previous researchers that had similar issue that caused by wet Choline chloride. However, I obtained similar results 😢. May I have some other suggestions or opinions that may solve the problem? Thanks in advance

Dear colleagues,

I'm looking for articles where I can find tests of food attractants used to monitor fruit flies. I am not looking for pheromone-based attractants.

We have already performed a series of tests where we tried to have a glue trap (containing aroma dissolved in propylene glycol) and the raw materials from which the aroma was made were used next to them (eg grapes and grape aroma). Fruit flies almost always chose the raw material itself and they were not interested in the aroma in the glue. Even after removing the raw material itself, the glue trap with aroma did not attract them.

I will be happy for any of your knowledge and articles on the topic.

Thank you.

Hello, can someone advise me ordering numbers (the best options are Sigma or Merck, but it could be even some another company) for Ethylen Glycol and Propylene Glycol solutions suitable as cryoprotectants for vitrification of porcine GV oocytes (or at least of some another mammalian species oocytes in general)?

Thank you.

Hi, I am working with PEGDA (polyethylene glycol diacrylate) for SLA 3D printing. Parts made from 100% PEGDA are transparent after production, while adding increasing amounts of propylene glycol to the pegda solution makes the final part appearing milky-white. Why does that happen? What causes this phenomenon? Please note that the liquid mixture of PEGDA/propylene glycol is also transparent before 3D printing.

Trans-dermal patches contain the drug intended for trans-dermal delivery, along with all kinds of (often petroleum derived) adhesives, plasticizers, inhibitors, and permeability enhancers. I'm trying to find any information about whether any of these other substances, adhesives, enhancers, tackifiers, etc. have been found to also pass through the skin along with the intended drug in small amounts. I have been able to find a lot of information about the composition of various patch systems, as well as trials of how effectively the drug intended for delivery is absorbed, but absolutely nothing about whether any of these other petrochemicals present in the patch matrix also pass through. Is anyone aware of literature on this? Has it just not been studied?

My assumption would be that very minimal trace amounts of the petrochemicals comprising the patch matrix pass into the body along with the drug intended for delivery ~~ but that this has been determined to be a safe amount for relatively short term use. I'm specifically asking this question with transgender people who use hormones in mind. A transgender person who uses HRT as part of transition and chooses trans-dermal delivery, trace amounts of these petrochemicals over a long period of time could cause significant issues...

And as a secondary question, I'm wondering if there are any studies into whether the enhancers//inhibitors in the patch also enable other environmental contaminants to pass through the dermis undigested. To give an example, when I have used trans-dermal patches intended to be worn for 1 week, by the end of the week the patch will regularly get water and soap under the edges, and sometimes the middle as I shower. This from what I've read is normal, and it's suggested to just apply pressure after showering to re-adhere the patch to the skin. So, potentially chemicals that are in shampoos, soaps, and conditioners are coming in contact with the area of skin "prepared" for trans-dermal absorption of xeno-molecules everyday.

Below is a summary of what I've found about the materials used to produce trans-dermal patches:

From what I can gather looking at patents and studies, estradiol trans-dermal patches are generally comprised of 4 main categories of chemical:

(1) The drug intended for delivery ~ Estradiol

(2) An inhibitor such as propylene glycol to disable the role of the dermis in enzymatically digesting xeno-molecules before they enter the body... propylene glycol inhibits the enzymatic reaction that causes oxidation of estradiol into estrone.

(3) An enhancer such as Oleic Acid that is intended to enhance permeability of the skin and facilitate transdermal movement of xeno-molecules

(4) Adhesive polymer, this varies a lot from patch to patch but as an example this is what I was able to find for the Vivelle dot HRT patch ~~~ acrylic adhesive, polyisobutylene, ethylene vinyl acetate copolymer, 1,3 butylene glycol, styrene-butadiene ribber, mineral oil, dipropylene glycol… excerpt from NOVARTIS FDA document https://www.accessdata.fda.gov/drugsatfda_docs/label/2000/20323S23lbl.pdf

And here is a list of the ingredients specific to one brand of Estradiol patch called "Vivelle Dot":

The Vivelle system comprises three layers. Proceeding from the visible surface toward the surface attached to the skin, these layers are (1) a translucent flexible film consisting of an ethylene Page 2 vinyl alcohol copolymer film, a polyurethane film, urethane polymer and epoxy resin, (2) an adhesive formulation containing estradiol, acrylic adhesive, polyisobutylene, ethylene vinyl acetate copolymer, 1,3 butylene glycol, styrene-butadiene rubber, oleic acid, lecithin, propylene glycol, bentonite, mineral oil, and dipropylene glycol, and (3) a polyester release liner that is attached to the adhesive surface and must be removed before the system can be used.

I'm currently working on a project that involves the simulation of CHT (Conjugated Heat Transfer) problems potentially leading to the evaporation of a water/glycol mixture.

Thus I would need to have the thermal properties (especially the coefficient of volume expansion) of both ethylene glycol (1,2-ethanediol) and propylene glycol (1,2-propanediol) in liquid and gaseous phases.

So far I've managed to find (relatively easily) the properties of the liquid components, but nothing regarding the gaseous components.

Could someone points me in the right direction for such data ?

Ethanol and propylene glycol are both used to preserve mites, and each have their drawbacks (i.e., evaporation and specimen distortion). Some people add a small amount of glycerol to vials of ethanol to prevent samples from drying out over time if containers prove less than perfectly airtight. Does anyone have experience with the long-term performance of ethanol/propylene glycol mixtures as preservatives for mites, and particularly for oribatids?

Propylene glycol has has flash point ~101 degC. What is the wt% of water needed to increase the flash point to ~150degC?

One of the companies recommends to dissolve their products in 50%/50% mixture of ethanol and propylene glycol and inject 15-75 ul intravenously (or intraperitoneally) in mice.

The stated benefits are high solubility of many compounds, far less inflammation of small vessels than with pure alcohols and a better handling (lower viscosity) than wth pure propylene glycol.

However, as far as I see, the use of this solvent mixture for i.v. injections appears to be almost absent from the literature: so far I've only seen a paper where it was used for i.p. (intraperitoneal) injections.

Does anyone know of this mix (50%/50% EtOH/PG) being used for i.v. injections in practice? If it has these benefits, why is it used so rarely? What are the safety levels and side effects?

I have carbonized items in propylene glycol how can I clean it out?

I have tried to derivatize 1-propanol with MSTFA, BSTFA and MTBSTFA. But I can not see any peak other than the blank peaks ( blank were prepared by pyridine and the derivatizing agent).

I derivatized 1,2 propanediol ( 1,2-PD) with MTBSTFA . 1,2 PD has two OH- group and acidic hydrogen was converted to TBDMS.

But what's wrong with the 1- Propanol ? Any idea will be highly appreciated !!!

Hello,

I am looking for PDMS membrane for propylene glycol and glycerol separation. I would highly appreciate if someone could recommend a supplier. 

Thank you

Hripsime

Hello Friends,

A quick question, can I use RO to separate propylene glycol from water? I am confused because it has low molecular weight and also not sure about the polarity. Can any body help me?

Thank you so much.

Actually I have a reproducibility issue.

I have a 7-component microemulsion system consisting of water and propylene glycol as the aqueous phase, ethanol and limonene as the oil phase and Tween60 as the surfactant.

I dissolve a certain amount of my drug at ~40C and then cool it down to 30C. Each time I get different amount of precipitates which means different amount of solubility.

Is it possible to have a range of solubility in microemulsion?

The taste on the product is evident. Is it toxic?

Hello everyone,

I am in internship in a laboratory to analyze and formulate flavors for e-cigarettes. I have to create a HPLC method to determinate the concentration in sucralose in our products. I already created one, with a protocol of many publications, with water. By the way, I would like to know more about it, and understand how the derivate product is ok for being analyzed in UV. I know that the aromatic chromophore is ok for UV but I would like to know more about it too. Our products are in Propylene glycol, glycerol and nicotina. That's why I can't try to analyze a sample with my standards in HPLC UV, there is no water in and I don't think that if I put water, the sucralose would react with it.

Moreover, I don't understand why I can't see this publication on ScienceDirect, because with my student access I usually can : "Benzoylation of sugars, polyols and amino acids in biological fluids for high-performance liquid chromatographic analysis."

If you have any ideas to try something with my standards and my samples, you can tell me !

Thanks for the help and have a good day,

Alice

Is it harmful or not?

I'm doing research about w/o caffeine micro emulsion (ME). I used 1 ml hot water to dissolve 400 mg caffeine but it crystallized and my ME become unclear or cloudy. I've tried to add 0,5 ml propylen glycol as cosolvent/cosurfactant but it still crystallized. I can't add more water because it can make my ME unstable and become emulsion. What should I do to prevent crystalization caffeine in my ME? Thank you. 

I have Imidacloprid and Propylene Glycol as contaminant both having 0.4 mM concentrations. I am doing experiment on Fenton process.  I came across with this journal citing that the requirement for H2O2 is 2.12 mg H2O2 per mg COD. I want to know the COD of my concentration without doing COD test. Is this possible?

Thanks.

i am having the data of temperatures, pressures and flow rates before and after the reaction. i need an equation which help me to identify conversion with respect to the change in above known variables.

I have a Charles River Endosafe PTS machine and I am looking to undertake an Endotoxin test for a chemical dissolved in Propylene glycol. So far I have not been able to find the dilution and what it can be dissolved in, in order to use in the PTS cartridges.  Does anyone have any advice?

i'm wondering why glycerine and propyleneglycol are used as solvents for e- liquids. of course, they are approved for consumation, they steam!

do you know which temperature is reached in the e cigarettes allowing evaporation? 

thanks in advance,

patrick schimpl

it is polyester synthesized using Adipic Acid, Phthalic Anhydride and Propylene Glycol

Dry or powder Propylene glycol vs its liquid form. Is there is any difference regarding ABSORPTION/METABOLISM?

Hi everybody,

I want to dissolve beta-sitosterol for animal experiment. I try to dissolve it in many solvents such as methanol, ethyl alcohol, polyethylene glycol, propylene glycol, DMSO, ... However, it is unsoluble in these solvents. 

Could everybody know what solvent can dissolve beta-sitosterol ?

Thank you so much

Typical pH probes have a temperature limit of 130 C and will see interference from the presence of Ag+ ions in our solution.

When collecting freshwater mussels in remote areas, it’s often impractical to use ethanol as a preservative. Especially for amateur collectors without access to laboratories.

Samples collected in the field might need to be stored briefly, then posted to a laboratory. The sample might consist of a snip of mantle tissue (possibly the whole body plus shell). On receipt, the tissue could be transferred to ethanol if necessary.

Some alternatives that have been suggested include  overproof rum, whisky, vodka or other strong spirits, and car antifreeze.

Are there proven options for freshwater molluscs, including freshwater mussels?

This paper describes options for insects (ok for molluscs too?):

Steininger S, Storer C, Hulcr J & Lucky, A. (2015) Alternative preservatives of insect DNA for citizen science and other low-cost applications. Invertebrate Systematics 29, 468–472. Prevention of DNA degradation is essential to conducting molecular analyses of field-captured specimens. This is especially important for projects that incorporate participation of non-specialists in research, such as agency monitoring of pests, or citizen science, where standard methods of preservation may be inaccessible. We examined efficacy of three common alternative products as a substitute for 95% ethanol or pure propylene glycol in preserving DNA: alcohol based hand sanitiser and propylene and ethylene glycol-based automobile antifreeze. We subjected Xylosandrus compactus ambrosia beetles (Coleoptera:  Curculionidae: Scolytinae) to each preservative for two or seven days under direct outdoor exposure and assessed relative quantity of intact DNA by performing real-time polymerase chain reaction amplification of a single-copy nuclear marker. Amplification was observed in all treatments and electrophoresis of the amplified product showed clear bands of the appropriate weight. Successful amplification of the target gene was verified by sequencing the amplified control. No statistically significant differences were found between the cycle threshold values of any treatment. Our results suggest that alcohol-based hand sanitiser and automobile antifreeze can successfully preserve DNA for short-term storage and serve as effective substitutes for laboratory-grade preservatives in citizen science projects, large-scale trapping projects or by professionals.

Hi,

To investigate management effects on biodiversity I am running a network of emergence and pitfall traps in a long-term conservation agriculture trial in Lilongwe, Malawi.

The climate is tropical and evapouration rates of collecting/preservation fluids in the traps is high.

A quick review of the literature suggests that 30% Propylene glycol should provide a collecting medium that has low evapouration rates and good preservative properties. 

My problem is that is Propylene glycol is very expensive in Malawi. I am wondering if, rather than replacing the P.glycol each trapping round, I can recycle the chemical by topping up the traps with water or a lower % P.glycol to compensate for evapouration? anyone tried this before?

Many thanks,

Pete

I have tried till today a lot of protocols (IHC world,...), using isopropanol or propylene glycol or both, but I haven't had any satisfaying results yet...The stain is scattering everywhere out of lipid droplets, red oil is precipitating and the slides end up all dirty. The last protocol I have tried is the following one: fix in formol 10% for ten minutes, then put in 100% propylene glycol for 5 minutes, stain with oil red O 1,8% in isopropanol ( dilution from stock solution 6:4) and then put in 85% propylene glycol for 2 minutes and rinse in deionized water for 1 minutes. I have also tried to later stain with Gill III hematoxylin for 30 seconds, but the results were even worse...  I am quite desperate about it ! Please if anyone met these kind of problems and managed to solve them, I would really appreciate her or his help :) Thanks in advance ! 

Dear all..

Kindly suggest the alternate for Propylene glycol which is commonly used as a vehicle control in the experiments (Genotoxicity and  antitumor studies) pertaining to EAC models..and also explain why propylene glycol is the most preferred vehicle control for comparison studies done using chemotherapeutic agents.

I have attached an article for better understanding..

Thank you

In current scenario, we have Propylene Glycol mixed with proper additive as an antifreeze. But to have freezing point depression by 50 degrees, the Antifreeze to Water proportion needs to be 1:1. I am in search of some chemical which can bring such depression in freezing point even at very low concentrations with water.

I am planning to treat a rodent species with thyroid hormones (T4 and T3) for 4 weeks using Alzet osmotic pumps (Model 2006). Does anyone have an established protocol or can give me some advice regarding the appropriate solvent (e.g. propylen glycol?) and the stability of the hormones in the pump during implantation. Regards and thanks in advance, yoshi.

I need to study the enzyme-solvent interaction and as a start decided to do a zymogram to check the viability of my protease in organic solvents selected (Propylene glycol, Polyethylene glycol and heptane). The problem is the enzyme is commercial and is available as granules which does not dissolve in either of the solvents.They get suspended and settle down in the stacking gel after loading. and also is it fine performing a SDS-PAGE  or a Native PAGE? 

What is the solubility of fluocinolone acetonide in propylene glicol (exact ratio)?

I have an ingredient list for a method I am interested in trying, but the exact quantities are lacking. If someone has made hydrogel from polyoxyethylene glycol, propylene glycol, urethane polymer and poluoxyalkyleneamine, I would be interested. Thank you.