SIMULTANEOUS DETERMINATION OF CHLORATE AND PERCHLORATE IN MILK BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

Abstract

A simple, selective, and sensitive method using hydrophilic interaction chromatography combined
with tandem mass spectrometry (HILIC−MS/MS) for simultaneous determination of perchlorate and
chlorate in milk was developed. The analysis was conducted on an HILIC column (150 mm × 4.6 mm,
3.5 μm) using a mobile phase consisting of acetonitril and 0.1% formic acid with gradient elution. The
detection was performed by MS/MS via electrospray ionization. The sample was extracted using ACN:
AcOH 1% (4:1). The extract was cleaned using C18 sorbent. Linear calibration curves were obtained
in the concentration range of 1 to 100 μg/L. The method detection limit was 0.15 μg/kg. The
recoveries of perchlorate and chlorate were all >80%. This method was successfully applied to the
quantitative determination of perchlorate and chlorate in 50 milk samples (milk powder, liquid milk
and yogurt).