Reliable Analyses of Water by Inductively Coupled Plasma Emission Spectroscopy. Analytical Chemistry Branch.

摘要

Reduction of stray light in the inductively coupled plasma emission spectrometer (ICPES) has greatly increased its reliability as a technique for the multielemental analysis of water. Because of interferences introduced by matrix elements,reliable analysis of some less-sensitive elements has been impractical at concentrations of =or < 200ppb. After surfaces in the secondary optical system were painted to prevent light scatter and the aperture at the primary lens was reduced in the ICPES,some interference corrections were reduced by more than one order of magnitude. Reduced interferences in the ICPES along with improved corrections by adding exact concentrations of calcium and magnesium to reagent blanks run during sample analyses have definitely improved the accuracy of this multielement analysis system. Observed background changes caused by the presence of magnesium were compensated for by adding matrix elements to calibration standards. Alcohol was added to standards,reagent blanks,and samples to overcome problems of background change during analysis of samples of unknown organic content such as municipal sewage.