混合胶束增敏火焰原子吸收光谱法测定植物叶片中的痕量铅

研究了十二烷基磺酸钠（SDS）和乳化剂OP组成的混合胶束对植物叶片中痕量铅测定的增敏作用,建立了植物叶片中痕量铅的火焰原子吸收光谱测定新方法,灵敏度比不加混合胶束提高了29%,该法快速,简便,廉价。结果表明：在0—5.0μg/mL范围内吸光度与Pb2＋浓度呈良好的线性关系,线性回归方程为APb＋SDS＋OP=0.0391C（μg/mL）＋0.0073,r=0.9974,检出限为0.006μg/mL。植物样品采取先灰化再对干灰进行快速消解的方法处理后,应用该方法对不同地区不同植物叶片中的铅进行测定,测定的相对标准偏差RSD为0.50%—3.90%,加标回收率为96.9%—103%,结果显示同一地区植物叶片中的铅含量与植物种类有关、不同地区同种植物叶片中的铅含量与交通密度有关。

Mixed Surfactants Enhanced Sensitizing Effect in Determination of Trace Lead in Plant Leaf Blade by FAAS

The sensitizing action of mixed surfactants（anionic surfactant sodium dodecyl sulfonate and nonionic emulsion） in determination of trace lead in plant leaf blade was studied,a new method to determine trace lead by flame atomic absorption spectrophotometry was established.The sensitivity raised 29% because of the addition of mixed surfactants.The method is rapid,simple and inexpensive.The lead in the range of 0—5.0μg/mL,absorbency is linear correlated with Pb2＋ concentration,the regression equation is APb＋SDS＋OP=0.0391C（μg/mL）＋0.0073 with the correlation coefficient r=0.9974 and.The limit of detection of 0.006μg/mL.Samples were treated with carbonization,cineration,digestion with mixed acid,and dissolution with HNO3.The trace lead in different plant leaf blade in different sampling stations was determined with satisfactory results.The relative standard derivation is 0.50%—3.90%,lead recoveries is 96.9%—103%,detection limit 0.006μg/mL was obtained.The concentration of lead was different in the same area dependent on plant species,and was different in different sampling stations was dependent on the traffic density.