HPLC standard (mixture) for performance qualification test?

Has anyone experience in standards or standard mixtures for HPLC with UV detection for performing performance qualification tests? I am searching for e.g. a mixture of 2-3 compounds that is...

31 December 2019 8,548 4 View

Derivatization of cortisol and metabolites for GCMS?

We have problems with analyzing cortisol by GCMS. After performing a 2 step derivatization (methoximation and silylation) with methoxyamine hydrochloride and MSTFA, we do not see peaks in the...

11 December 2017 4,695 9 View

Does anybody know if there is a company which sells an amino acid standard with more than 30 amino acids?

Hi everybody! I have a question: I need an amino acid standard mixture for quantification experiments on a GC! We have a standard with 20 amino acids, but I would like to have one with more...

01 February 2016 3,347 3 View

Looking for Materials with high thermal expansion coefficient and high temperature resistance?

03 March 2021 8,272 1 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 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

Is There Any Feasible Method To Test Fluorescent Compounds Other Than Fluorescence Spectrometers ??

Is There Any Feasible Method To Test The Efficiency Of Fluorescent Compounds Other Than UV Spectrometers ? Suggestions Would Be Appreciated !

02 March 2021 5,785 3 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

How to compare different concentrations of nanoparticles for characterization from ICP-MS?

I took measurements of different concentrations of 15 nm and 5 nm Au nano particle solutions. I'm trying to determine which concentration I measured gives the best reading overall. I also...

02 March 2021 7,626 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

Does anyone know HRM channel in a 2 plex QIAGEN Rotor- Gene Q qPCR can be used as a separate channel?

I am going to have 3 different probes in my qPCR work that I am going to do. But I realized that the machine we have in the lab is a Rotor-Gene Q 2plex HRM Platform, saying it has green, yellow,...

01 March 2021 8,544 1 View

I have designed reflectarray element and feeding it though Horn Antenna on HFSS. After full wave simulation, I am not getting desired results?

I have designed reflectarray element to generate OAM beams at 5.8GHz and feeding it though Horn Antenna on HFSS. After full wave simulation, i am not getting desired results i.e Radiation pattern...

01 March 2021 9,701 5 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