𝔖 Bobbio Scriptorium
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High-sensitivity liquid chromatography–combustion isotope ratio mass spectrometry of fat-soluble vitamins

✍ Scribed by Richard J. Caimi; J. Thomas Brenna

Book ID
102905996
Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
623 KB
Volume
30
Category
Article
ISSN
1076-5174

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✦ Synopsis

Abstract

The sensitivity of high‐precision liquid chromatography/combustion isotope ratio mass spectrometry (LC/C‐IRMS) was improved by more than two orders of magnitude by modifications which permit optimization of flows. The lower limits for high precision are about 3 μg of analyte on‐column for flow injection and LC modes. Pneumatic aerosol spray coating was implemented and compared with simple dip coating. The signal enhancement for aerosol compared with dip coating is up fourfold at higher levels but drops to less than twofold at lower levels, while the dynamic range is extended at higher levels by fourfold at high sample load levels. LC separations for underivatized tocopherols, retinyl acetate and ergocalciferol are demonstrated with precision and accuracy of about δ^13^C < 2.5% for replicates. This work demonstrates sensitivity useful for a wide range of LC analyses and extends high‐precision LC/C‐IRMS to the determination of several fat‐soluble vitamins.

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