Abstract: Sample pretreatment is a key step in element testing, which directly affects the precision and accuracy of analytical results. In order to meet the requirements for the detection of various elements, in this study, we used microwave digestion combined with inductively coupled plasma-mass spectrometry (ICP-MS) operated in the collision reaction mode to determine the content of multiple elements in milk powder, and investigated the influence of sample pretreatment conditions (acid removal time, sample size, and the amount of residual acid) on the detection results. Compared to removing acid mist only, better results were obtained under the following conditions: acid removal temperature was 160 ℃, acid removal time was 97.5 min, and sample size was 0.250 0 g, and the amount of residual acid was 1.0 mL. This pretreatment process is characterized by good stability, high precision and high accuracy.

Key words: inductively coupled plasma-mass spectrometry; milk powder; acid removal time; residual acid amount; multiple elements

摘要： 样品前处理是元素检验中的关键步骤，直接影响分析结果的精密度和准确度。为了满足对各种元素的检测要求，采用微波消解法，使用电感耦合等离子体-质谱（inductively coupled plasma-mass spectrometry，ICP-MS）仪的碰撞反应模式，测定乳粉中的多元素含量，考察样品前处理中不同赶酸时间、不同称样量和不同赶酸剩余量对检测结果的影响。结果表明：赶酸温度160 ℃、赶酸时间97.5 min、称样量0.250 0 g、赶酸剩余量1.0 mL时的检测结果明显优于仅赶走酸雾的处理结果，该前处理过程具有稳定性好、精密度高、准确性高的优点。

关键词: 电感耦合等离子体-质谱法；乳粉；赶酸时间；赶酸剩余量；多元素