摘要
为了建立适用于自动固相萃取结合高效液相色谱法测定土壤中苯并(a)芘含量的不确定度分析方法。采用如下方法:样品用正己烷-丙酮索式提取后,加入适量吸附剂和去离子水,经过固相萃取小柱净化、浓缩定容,再用Agilent Eclipse XDB-C18色谱柱(4.6×150mm×5μm)对苯并(a)芘含量进行分析,流动相以乙腈-水(体积比为80∶20)进行等度洗脱,采用紫外检测器检测,外标法定量。依据JJF 1135—2005《化学分析测量不确定度评定》中相关规定,考查称量、定容体积、标准曲线、仪器测量重复性和回收率等引入不确定度的主要因素,并对不确定度的各分量进行计算和合成。结果表明:当土壤样品中苯并(a)芘含量为6ng/kg时,在95%的置信区间下,其扩展不确定度为0.50ng/kg(k为2)。评定结果表明,标准曲线拟合和标准溶液配置产生的不确定度对合成不确定度的影响较大,而样品称量所引入的不确定度较小,可忽略不计。得出:该评定方法客观准确,适用于固相萃取结合高效液相色谱法测定土壤中苯并(a)芘含量的不确定度分析,对检测结果准确度的提高具有参考意义。
In order to establish an uncertainty analysis method for determination of benzo(a)pyrene in soil,automatic solid phase extraction combined with high performance liquid chromatography(HPLC)was adopted.Using the following methods:after Soxhlet extraction with hexane and acetone,samples were added adsorbent and deionized water,after solid extraction purification and enrichment,using HPLC to analyze the benzo(a)pyrene content.The mobile phase of HLPC was acetonitrile and water and using UV detector and external reference method to determine content.According to the relevant provisions in 'Chemical Analysis Uncertainty'(JJF 1135—2005),the factors influencing uncertainty including weighing,constant volume,standard curve,measurement repeatability and recovery rate were considered and the uncertainty of each factor was calculated.The results showed that the standard curve and standard solution had great influence on the uncertainty but the influence of weighting is small and negligible.It is concluded that this method is objective and accurate.It is suitable for the determination of the content of benzo(a)pyrene in soil by solid phase extraction combined with HPLC.It has reference significance for improving the accuracy of the detection results.
出处
《油气田环境保护》
CAS
2017年第5期41-44,47,共5页
Environmental Protection of Oil & Gas Fields
关键词
不确定度
苯并(A)芘
固相萃取
高效液相色谱法
土壤
uncertainty
benzoapyrene
solid phase extraction
high performance liquid chromatography
soil
