1996 Volume 45 Issue 11 Pages 1005-1012
Analytical performance of a long torch for axially (end-on) viewed horizontal inductively coupled plasma atomic emission spectrometry (ICP-AES) was examined using a high resolution echelle spectrometer with wavelength modulation and second derivative detection.Optimum operating conditions were studied for 24 elements having spectral lines between 210 and 770 nm. Compared to conventional torch measurement, net emission intensities of the elements increased by 2040% and background intensities of water blanks decreased by 3050%. The values of S/σ (S:signal intensity of an analyte, σ:standard deviation of the background intensities) and BEC(background equivalent concentration) were improved for all of the elements.Limits of detection were improved by 1.5-fold (Be) and 6.9-fold (Al). Repeatability given by the relative standard deviation of the net emission intensities was also improved for each element. The dynamic range for each element was about five orders of magnitude. The emission line (427.673 nm) of Ca showed interference by Na of above 50mg dm-3, but was scarcely affected by phosphoric acid of below 3 v/v%. Determination of the main and trace elements of the standard reference material, NIST SRM 1643c (water), gave analytical values which agreed well with its certified values.
