关键词: 电感耦合等离子体质谱；铅；检出限；超声清洗

Abstract: By analyzing some factors involved in the determination of lead in milk powder by inductively coupled plasma mass spectrometry (ICP-MS) such as containers and reagents used, an ultrasonic cleaning method was established to effectively reduce the blank value. The method gave a detection limit of 0.005 mg/kg, which was much lower than that (0.02 mg/kg) of traditional methods. The recoveries of samples spiked at concentration levels of 0.005–0.015 mg/kg ranged from 86.9% to 119.0% with relative standard deviations (RSDs) of 3.1%–12.3%, meeting the requirements for methodological validation. Hence, the method proved to be overall feasible and suitable for the detection of lead in milk powder with reduced detection limit.

Key words: inductively coupled plasma mass spectrometry; lead; detection limit; ultrasonic cleaning