Effects of acid type and concentration on the determination of 34 elements by simultaneous inductively coupled plasma atomic emission spectrometry

A mixed acid consisting of 11.6% HCl/2.8% HNO3 proved superior to 2 to 10% HCl, HNO3, and H2SO4 alone in chemical compatibility and storage characteristics for simultaneous inductively coupled plasma atomic emission spectrometric (ICP-AES) determination of 33 elements admixed up to concentrations of 100 μg/mL each. A 2% aqua regia solution appeared to be adequate below 10μg/mL of all these admixed elements plus silver. Use of the mixed acid generally also allowed for more reproducible interelemental k factors. Less sensitive elements and elements whose lines were in the vacuum ultraviolet were not as reproducible. A two-point standardization procedure was adequate, and k factor values agreed within 10% only over a specific concentration range. A practical procedure to define the range of determination was developed using the 11.6% HCl/2.8% HNO3 acid solvent. 24 references, 11 tables