文摘
Simultaneous detection of two classes of dyes possessing different chemical properties is difficult. In this study, through negative/positive ion switching mode, simultaneous determination of four typical acid orange dyes and three typical basic orange dyes was achieved by a single high-performance liquid chromatography鈥搕andem mass spectrometry (LC-MS/MS) method, and the analytical efficiency of multiresidues identification was greatly improved. To enhance detection sensitivity, the sample pretreatment conditions and HPLC-MS/MS determining conditions were carefully optimized. Under optimal conditions, good linearity was obtained over the range of 5鈥?00 渭g L鈥? with a correlation coefficient (R2) >0.9998. Limits of detection (LODs) and limits of quantification (LOQs) of the seven dyes were 0.5鈥?.0 and 2.0鈥?.0 渭g kg鈥?, respectively. The recoveries of the seven dyes in soybean products and marinated eggs were 74鈥?26% with relative standard deviations (RSDs) of 2.22鈥?5.4%, suggesting the developed method is promising for the accurate quantification of the seven dyes at trace levels in foods.
Keywords:
acid orange dyes; basic orange dyes; foodstuffs; LC-MS/MS; negative/positive ion switching mode