Determination of mercury in organic solvents and gas condensates by mu flow-injection - inductively coupled plasma mass spectrometry using a modified total consumption micronebulizer fitted with single pass spray chamber

摘要

A high-throughput flow-injection - inductively coupled plasma mass spectrometry (ICP MS) analytical method was developed for the determination of mercury in gas condensates and carbon-rich solvents.The sample (undiluted or diluted 10-fold) was introduced via a modified total consumption micronebulizer working at a flow rate of 30 mu l min~(-1) and fitted with a singlepass spray chamber.This low flow rate and the addition of oxygen (70 ml min~(-1)) assured the plasma stability and reduced the carbon build-up on the interface and on ion lenses.A limit of detection of 0.5 ng g~(-1) (2.5 mu l sample) was obtained owing to the reduction of dead volume and sample dispersion (peak-width was 3 s at half-height) in the liquid pass of the nebulizer.The elimination of the memory effect reduced the washout time down to 30 s which resulted in a throughput of ca.60 h~(-1).The method was validated by the analysis of 3 gas condensates by cold vapour atomic absorption spectrometry.