红外光谱法测定水产品中石油烃残留

Determination of petroleum hydrocarbon residues in aquatic products by infrared spectroscopy

目的建立微波消解前处理结合红外光谱法测定水产品中石油烃残留量的分析方法。方法试样经微波消解后,用四氯乙烯液-液萃取,萃取液经活化硅酸镁和无水硫酸钠去除干扰后,氮气吹至近干,四氯乙烯定容,经红外光谱检测,记录2930、2960、3030 cm^(-1)处的吸光度值,计算出石油烃在水产品中的含量。结果石油烃在0.4~6.4和5.0~100.0 mg/L范围内呈良好的线性关系(r^(2)>0.998),使用6%活度的硅酸镁填充吸附柱至60 mm时,吸附效率最佳,在此条件下测试的方法检出限(limit of detection,LOD)为0.18 mg/kg,定量限(limit of quantitation,LOQ)为0.57 mg/kg,相对标准偏差(relative standard deviations,RSDs)在1.99%~6.36%之间,加标回收率在91.5%~110.5%之间(n=5)。结论该方法具有检测范围宽、稳定性好、准确度高的优点,能满足水产品中石油烃残留量检测需要。

Objective To establish an analytical method for the determination of petroleum hydrocarbon residues in aquatic products by microwave digestion pretreatment combined with infrared spectroscopy.Methods After digested by microwave,the sample was extracted by liquid-liquid extraction with tetrachloroethylene,and the extraction solution was activated by activated magnesium silicate and anhydrous sodium sulfate,then blown to nearly dry with nitrogen,and the volume was fixed with tetrachloroethylene,and then determinate by infrared spectroscopy,the absorbance values at 2930,2960 and 3030 cm^(-1) were recorded to calculate the content of petroleum hydrocarbons in the organism in aquatic products.Results The petroleum hydrocarbon had good linear relationship(r^(2)>0.998)in the range of 0.4‒6.4 and 5.0‒100.0 mg/L,under the optimum adsorption condition of which the column was filled with magnesium silicate with 6%activity to 60 mm,limit of detection(LOD)was 0.18 mg/kg,limit of quantitation(LOQ)was 0.57 mg/kg,and the relative standard deviations(RSDs)were 1.99%‒6.36%,and the recoveries were 91.5%‒110.5%(n=5).Conclusion The method has the advantages of wide detection range,good stability and high accuracy,and can meet the detection needs of petroleum hydrocarbon residues in aquatic products.