Why am I getting singlet instead of triplet for my sample?

Both 1H and C13 NMR values of my sample can be assigned to a known molecule except at one place. From reference values and theoretical point of view, a methine proton (CH) near to a methylene...

10 November 2016 2,761 5 View

TLC Solvent systems for methanol extract of bark?

Kindly share your experience, if any, with bark phytochemistry. It would be grateful if I get a good tlc mobile phase for studying methanol extracts of bark that is known to contain polyphenols.

08 September 2015 9,600 0 View

How can Soxhlet extraction be explained using a mixture of solvents?

05 June 2015 2,921 8 View

Is there a characteristic C13 peak in the NMR spectra for terpenoids and steroids?

Please tell me if there is any in order to distinguish the spectra of terpenoids and steroids.

04 May 2015 9,644 9 View

Does drying affect vitamin content of plant samples?

Can vitamins be estimated/analyzed from dried samples preferably dried at 40 degree celsius?

01 February 2015 1,744 11 View

Is there any negative impact of diethyl amine while using in column chromatography?

I would like to know if there is any especially while purifying a molecule and also in obtaining NMR spectrum of thus purified molecule. Does the presence of trace DEA or its impurities while...

01 February 2015 4,116 5 View

Has anyone ever used cheaper/small/moderate pressure pumps to increase the flow rate in columns?

I would like to have one for my RP open columns. Please share your experience and thoughts. Also please share what kind of pump you have employed for your work.

31 December 2014 5,521 5 View

Any easy explanatory notes about HMBC?

Looking for good explanatory notes to understand HMBC. Simple explanation with worked problem is also much appreciated.

11 December 2014 2,306 11 View

How do I remove perchloric acid from my samples so that it can be loaded onto HPLC columns?

It would be very helpful for my work if anyone can suggest a way to remove perchloric acid from my sample for further chromatographic studies.

10 November 2014 9,563 3 View

Does the accumulating CO2 levels become toxic to yeast during fermentation?

What will happen to the yeasts if the vessel carrying out yeast fermentation is tightly sealed? Will the rising level of CO2 inside the vessel be toxic to the growing yeasts or the yeasts have a...

06 July 2014 5,557 8 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View

How optimize the Size Exclusion Chromatography?

Hello! I'll do a size exclusion chromatography, but I only have an open column, and I'll perform the peptide extraction from yeast, using buffer lysis (sodium phosphate 50 mM/NaCl 30 mM/DNAse and...

01 March 2021 2,215 2 View

Precipitate after adding laemmli buffer to protein solution containing Potassium Acetate?

Hi, I am running a size exclusion chromatography experiment with a buffer containing Potassium Acetate as a salt. I analyse these fractions through SDS-PAGE. After boiling my SEC fractions in...

01 March 2021 2,622 3 View

Any research papers for extraction of nutrient deprivation on macroalgae? Analysed by HPLC-UV and GC/MS. Possibly from macroalgae genus Rhizoclonium?

I am doing my thesis on the nutrient deprivation on the macroalgae Rhizoclonium sp. I will be analysing the levels over a period of roughly 5 days by HPLC-UV and GC/MS. I will be using seawater as...

28 February 2021 6,477 1 View

1 nm thick MgO thin-film to be deposited on Si wafer using thermal evaporation. What will be the optimum deposition conditions?

Favourable conditions of base pressure, rate of deposition. Also, by which characterisation technique to be used to verify the thickness of the deposited film.

28 February 2021 3,640 3 View

Unknown debris sheets observed in cell culture flasks?

Hi, We culture neural progenitor cells in T175 culture flasks coated with PLO-Laminin. We have successfully grown these cells with our protocol for months. Recently, we observed large sheets...

25 February 2021 3,443 4 View

What is a good reagent for lentiviral plasmid transfection in HeLa cells?

I have been using Lipofectamine 2000 but was hoping there may be a better protocol or one for something like Lipofectamine PLUS reagent.

24 February 2021 1,633 4 View

How can plant phytochemistry be included in discussions about whole plant traits?

I am using the concept of plant functional traits (Cornellisen et al., 2003) in a paper. Considering descriptions for whole plant traits (life history; life form; growth form; plant height;...

24 February 2021 6,831 5 View

Do you kow of any database containing data on retention time, log P and polarizability for a large number of molecules?

Hi, I am a chemistry undergraduate doing my dissertation project on HPLC. In my project, I need to predict the HPLC retention time of 20 aromatic molecules, the calibration set. To do this I will...

24 February 2021 2,602 1 View

How to prepare a thin polymer film by post-polymerization/crosslinking?

24 February 2021 2,362 5 View