Abstract:A method for the determination of phosphorus, arsenic, and selenium contents in foods by inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS) was established. The common mass spectral interference and ionization efficiency during measurements of phosphorus, arsenic, and selenium were analyzed, and the standard mode (no gas), helium mode, hydrogen mode, oxygen mode, and double quadrupole detection mode were compared. The most accurate results for phosphorus and selenium detection were obtained by using the oxygen mode and dual mass spectrometry, and the helium mode could be used for the accurate detection of arsenic. According to the optimized detection conditions, the isotopes of M entered the collision cell after Q1, and reacted with oxygen to form the oxide MO, which entered into Q2. Mass transfer of the tandem mass spectrum could almost eliminate all interference. The results showed that good linear calibration curves were obtained in the range of 2.0~500 μg/L for phosphorus and 0.5~200 μg/L for arsenic and selenium, and the correlation coefficients were over 0.9995. The recoveries were in the range of 94.0~101.5%, and the relative standard deviations (RSDs%) were not more than 2.1%. Finally, national standard substance milk powder sample (GBW10017) and Spirulina (GBW10025) were analyzed using this method, and the results were all within the standard value range. Therefore, the method can meet the requirements for the accurate detection of phosphorus, arsenic, and selenium in food.
