Missing peak and ions of 3MCPD

I have had prepared serial dilutions of 3MCPD standard and internal standard (3MCPD-ds) for calibrating my GC-MS (Agilent ) according to EU 14573:2004. But after injection I got nothing. Non of...

03 April 2013 214 3 View

3MCPD-d5 ions missing.

I have prepared 3mcpd in 20% NaCl solution standard and 3mcpd-d5 in water as internal standard. After injection on my GC-MS 5975, the ion of 3MCPD appeared with good response but with the...

02 March 2013 1,688 11 View

HPLC failure.

Yesterday I came to my instrument ABSciex Triple Quad 5500 coupled to Agilent HPLC 1290 to initialize the profile, but it kept giving me an error message that said: "Failure to initialize binary...

01 February 2013 6,376 11 View

Dioxin analysis

There is a plan to introduce Dioxin analysis in our Lab. I need your recommendation for Which instrument we should go for.

31 December 2012 7,496 6 View

I am searching for a SOP concerning steroids analysis in meat products using LCMSMS, Can anyone help?

SOP ( Standard Operating Procedure )

10 November 2012 8,322 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

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

No title

01 March 2021 3,905 5 View

What test should I use to compare two or three means, if data is not normally distributed but sample size is > 30 in each group?

I personally feel this as a most confusing question. As per my understanding, if sample size is > 30, and sample is skewed, we can still use paramteric approach, as it will follow Z...

01 March 2021 1,587 6 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

I want to performe MALDI-TOF MS for bacterial identification, I would appreciate it if anyone can tell me the matrix solution preparation protocol ?

based on what I've studied on multiple papers, for peptide and protein identification Alpha-cyano-4-hydroxycinnamic acid (CHCA) is an appropriate matrix to use, I also know that the CHCA powder...

26 February 2021 6,799 3 View

Sample size determination for non-parametric tests?

How do I run a a priori sample size determination for non-parametric tests, like the Mann-Whitney U-test and the Kruskall-Wallis or other non-parametric tests that accord with the unpaired t-test...

24 February 2021 166 6 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