INJECTION METHOD FOR THE SEQUENTIAL DETERMINATION OF BORON AND SEVERAL METALS IN WASTEWATER SAMPLES BY INDUCTIVELY-COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY

Boron and nine metals (Ba, Cd, Cu, Fe, Mn, Mo, Ni, Zn) can be determined in waste waters of medium and high salt concentration by inductively-coupled plasma atomic emission spectrometry. An injection method was applied in order to achieve analysis times of about 1 min per determination, and to allow trace analysis in solutions having salt concentrations up to 20 mg ml-1, when a Meinhard nebulizer is used with a low-power argon plasma. When 500-μl aliquots are injected and the peak heights of the amplified photomultiplier signals are measured, the detection limits for the elements tested range from 0.05 to 0.4 μg ml-1. Matrix effects caused by sodium nitrate (20 mg ml-1) are less than 20%, provided that a peristaltic pump is used for feeding the nebulizer. Matrix effects can be decreased by using simultaneous background measurement. The plasma-injection method is applicable to boron and metals in the range 0.05-20 μg ml-1. © 1979.