On-line sample preparation for multiclass vitamin, hormone, and mycotoxin determination in chicken egg yolk using LC-MS/MS.

Hen egg yolk from chicken eggs were examined for their mycotoxin, hormone, and fat-soluble vitamin content. A method was developed for multi-class analysis of egg yolk using a dilute/precipitate, centrifuge, and shoot process coupled with on-line sample clean-up using restricted access media with LC-MS/MS. Matrix effects were evaluated and a standard addition protocol with internal standards was chosen for analyte quantitation. With some minor exceptions, the method displayed good linearity (R2 > 0.99), with appropriate limits of detection (0.05-10 ng/g) and limits of quantitation (0.15-30 ng/g) for the analytes tested. Overall, it was discovered there was some variation between the different types of eggs tested in these experiments, especially with regard to their fat-soluble vitamin contents. Low-level mycotoxins were detected in most of the eggs tested. The challenges associated with developing a multi-class compound determination from a single analytical run were elucidated.