Determination of Trace Inorganic Anions on Printed Circuit Board by Ion Chromatography

The sample of printed circuit board was soaked in a mixed solution of iso-propanol and water (3+1) to extract the anions Cl-,Br-,NO-3 and SO2-4 from the board,and the interference of iso-propanol to the determination was eliminated through the on-line pretreatment.The anions were then determined by ion chromatography.Influential factors to the separation of the anions (i.e.concentration of eluent and time of on-line transferring of sample solution) were studied.Under the optimum conditions,linearity of the calibration curves found were in the range of 20.0 to 800.0 μg·L-1 for all the 4 anions.Precision of the method was tested with mixed standard solutions having the mass concentration of 100.0,800.0 μg·L-1.RSD′s (n=6) of values of peak area measured for Cl-,Br-,NO-3 and SO2-4 were 0.7%,0.8%,0.7%,1.8% and 0.1%,0.1%,0.1%,0.7% respectively.