ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
To evaluate the accuracy of glucose methods, we have set up an isotope dilution gas chromatographic mass spectrometric method where methyloxime trimethylsilyl derivatives of monosaccharides were separated with a SP-2100 fused silica column. An autodiluter was found suitable for delivering aliquots for derivatization: CV of 0.13% (aqueous) and 0.24% (serum). Ions at m/z 319 (non-labelled) and 323 (deuterium-labelled) were selected for glucose, galactose and mannose, and at m/z 307 and 311 for fructose. Optimization of ion monitoring with a Finnigan 4000 gas chromatograph mass spectrometer 6110 data system was limited to one scan per second without full compensation for 0.1 u shifts. A CV of 0.65% in isotope ratios was obtained for 30 injections (three per vial) of one glucose standard. A similar variation between duplicate injections was obtained with serum. Glucose measurements on 36 serum specimens (six individuals) were made by gas chromatography mass spectrometry and by both a manual (reference) and a flow-through method using hexokinase and glucose-6-phosphate dehydrogenase. Mean glucose by gas chromatography mass spectrometry was 5.57 mmol l-1; bias was -1.7% manually and +1.2% by the automated method. Average concentrations (mmol l-1) of other hexoses were low: mannose (0.058), fructose (0.015) and galactose (0.005). Glucose measurements of two control sera bracketed with standards showed satisfactory agreeement between the three methods. CV of 1.2 to 1.4% by gas chromatography mass spectrometry indicate that further refinements are required.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200100306
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