Analysis of Perchlorate in Milk Powder and Milk by Hydrophilic Interaction Chromatography Combined with Tandem Mass Spectrometry

A simple, selective, and sensitive method using hydrophilic interaction chromatography combined with tandem mass spectrometry (HILIC−MS/MS) for quantifying perchlorate in milk powder and milk was developed. The analysis was conducted on an Inertsil HILIC column (150 mm × 3.0 mm, 3.5 μm) using a mobile phase consisting of methanol and 0.1% formic acid (60:40, v/v). The detection was performed by MS/MS via electrospray ionization. Linear calibration curves were obtained in the concentration range of 2.00 × 10−2 to 8.00 μg/g and 4.00 × 10−1 to 20.0 μg/L for perchlorate in milk powder and milk, respectively. The method detection limit was 4.00 × 10−3 μg/g for milk powder and 8.00 × 10−2 μg/L for milk. The recoveries of perchlorate in milk powder and milk were all >90%. This method was successfully applied to the quantitative determination of perchlorate in milk powder and milk.