Simultaneous quantitation of homocysteine, cysteine and methionine in plasma and urine by liquid chromatography-tandem mass spectrometry

Abstract

Background A method utilizing liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) has been developed and evaluated for the determination of total homocysteine, cysteine and methionine in plasma and urine. The simultaneous measurement of homocysteine and methionine concentrations may help explain the underlying mechanism responsible for hyperhomocysteinaemia.

Determination of Thiols in Yeast by HPLC Coupled with LTQ-Orbitrap Mass Spectrometry after Derivatization with p-(Hydroxymercuri)benzoate

“…The integration windows for each of the scan methods are shown in Table 1, and the LODs of The absolute LODs for the thiols were in the sub-picomole range, and they were better than the LC-UV methods (11,12,33), most of the MS based detection methods (5,(34)(35)(36)(37)(38)(39), and the results via fluorescence measurement (40,41).…”

A rapid LC-FTMS method for the analysis of cysteine, cystine and cysteine/cystine steady-state redox potential in human plasma

“…[ 13 C 2 , 15 N]-GSH was synthesized utilizing FMOC solid-phase synthesis on a 433A Peptide Synthesizer using HOBt/DCC activation for coupling. [1,2-13 C, 15 N]-glycine was coupled to a blank HMP resin using HATU activation for coupling. The remaining residues were added on the 433A Peptide Synthesizer.…”

“…Samples showing any evidence of hemolysis were discarded. One hundred microliter aliquots were stored at −80° C. Aliquots were thawed and 3.0 µL of isotopic standard (500 15 N 2 ]-GSSG) was 4added. Protein was precipitated by adding 2:1 (v:v) of acetonitrile to the plasma and centrifuging at 13,000 x g for 2 min.…”

“…The assays dependent upon amine reagents are limited by the ability to obtain detection without interference from other amine compounds, while the electrochemical methods are limited by the stability of Cys during processing and storage. Recently detection by mass spectrometry has been used to determine total Cys without distinguishing between Cys and CySS [14,15].…”

Two-dimensional high performance liquid chromatography for determination of homocysteine, methionine and cysteine enantiomers in human serum

“…The determined concentrations of HCSH, Met and CSH in human serum were about 13, 25.5 and 261 mol L −1 and in urine they were about 7.2, 5.9 and 260 mol L −1 . Their concentrations in human plasma were similar (11.5 mol L −1 for HCSH, 6.1 mol L −1 for Met and 269 mol L −1 for CSH) [2]. Elevated plasma HCSH levels are associated with a higher risk of cardiovascular and cerebrovascular diseases [3].…”