除草剂混合标准溶液中标准物质稳定性研究

摘要

A mixed standard solution was obtained with 28 kinds of herbicide reference materials ( DR Company , German) .It was transferred into 20 mL-screw brown sample bottles with PTFE lining cover , and stored away from light at -18℃.Each component value was determined by liquid chromatography -tandem mass spectrometry ( LC-MS/MS) in different storage time .The results showed that the standard deviation of each reference material level was in the range of 12~73μg/L in 90 days.The maximum relative standard de-viation (RSD) was 3.04%(n=5), and the relative uncertainty of measurement was less than 5.60%.In the 95%confidence interval , the value of each reference material was in the range of ( 1 000 ±113 ) μg/L with no significant measuring deviation .The diluted mixed packing reference materials could store for 90 days within the valid period .%选取德国DR公司生产的28种除草剂标准物质，将其配制成混合标准溶液后转移至20 mL带聚四氟乙烯衬盖的棕色螺口样品瓶中，于-18℃避光贮存，采用液相色谱串联质谱法测试各组分量值随贮存时间的变化。结果表明：在90天内，标准物质各组分量值的标准偏差在12～73μg/L范围内，最大相对标准偏差为3．04％（n＝5），测量结果的相对不确定度小于5．60％。在置信度为95％时，标准物质各组分量值在（1000±113）μg/L范围内，测量的偏差不显著。在不超过标准物质的有效期内，稀释混合分装后的标准物质可保存90天。