High performance ultra trace analysis in molybdenum and tungsten accomplished by on-line coupling of ion chromatography with simultaneous ICP-AES
For the characterisation of trace elements in high purity Mo and W analytical methods with a detection limit in the ng/g-range have to be used. Today mass spectrometric methods are state of the art for such applications. However, these methods in case of refractory metal analysis are time consuming, expensive, limited by isobaric interferences and therefore not very suitable for quality control in an industrial laboratory. With respect to these drawbacks a cost and time efficient method was developed by on-line coupling of an ion chromatographie system to a simultaneous ICP-AES (Inductively Coupled Plasma — Atomic Emission Spectrometry) instrument. Within the limitations caused by the hard- and software of the system all parameters such as eluent concentration and flow rate, nebulizer and plasma gas flow, sampling frequency, integration time and the number of simultaneously measured emission lines were optimised. Further enhancement of the sensitivity was achieved by the use of an ultrasonic nebulizer pushing the detection limits down to the pg/g- and ng/g-range for 22 representative elements.
Key wordsultra trace analysis molybdenum tungsten on-line coupling ion chromatography ICP-AES
Unable to display preview. Download preview PDF.