Chau Phuong Bui

4 Questions 6 Answers 0 Followers

Questions related from Chau Phuong Bui

What are the reasons for the LCMS autosampler broken (bending needle, sample transport broken)?

Hello everyone! I would like to ask you about the reasons for autosampler break. The previous day, I used the LCMS machine and I did not put a sample in the rack at which the autosampler came...

31 January 2024 2,487 2 View

How to take an exact volume of methanol with micropipette?

Hello, When working with methanol, I noticed that I could never take the exact volume of methanol with micropipette. Is there any other tool or method that could solve this problem? Many thanks...

24 July 2023 9,964 11 View

Peptide CCK8 in sulfated form at Tyrosine is degraded to unsulfated form (-SO3 ) in mass spectrum. What should I do to keep the sulfated CCK8 stable?

Hello, My standard is (Tyr[SO3H]27)Cholecystokinin 8 from Sigma. (molecular isotopic mass: 1142.35) I make stock solution in 0.05M aqueous NH4OH as COA. I have tried many solvent for the stock...

19 July 2023 3,617 0 View

Peptide and ionization in mass spectrometry - Which adduct ion could be formed?

My peptide is Cholecystokinin (CCK8), MW=1142.35 (COOH-D-Y-M-G-W-M-D-F-NH2). Stock solution in NH4OH 0.05M and working solution in acetonitrile. I do MS infusion at conc. 500 ng/ml in...

23 June 2023 7,108 11 View