Determination of Micro-Amounts of Lead in Lotus Plumule by Differential Pulse Anodic Stripping Voltammetry

Lead in lotus plumule was determined by the differential pulse anodic stripping voltammetry using screen-printed microelectrode.Lotus plumule sample was digested in a micro-wave oven under 500 kpa for 1 h.Various factors affecting the determination i.e.,the condition of sample digestion,pH of the sample solution,potential and time of enrichment,pulse intensity and periodicity etc.were studied and optimized.In an acetate buffer of pH 3.6,and by enrichment at -1.1 V for 10 s,linearity was kept between the peak current and concentration of Pb2+ in the range from 1 μg to 1 mg per liter (r=0.996).In its application to the analysis of substantial sample of lotus plumule,values of RSD′s (n=5) and recoveries found were less than 5% and in the range of 101.9% respectively.