Multipumping flow system for improving hydride generation atomic fluorescence spectrometric determinations

The advantages of using membrane micropumps rather than peristaltic pumps to introduce both sample and reagent solutions for hydride generation atomic fluorescence spectrometry are discussed. Arsenic was used as a test analyte to check the performance of the proposed manifold. Sample and reagent consumption was reduced 8–9 fold compared with continuous mode measurements made with peristaltic pumps, with no deterioration in sensitivity. The calibration graph was linear in the 0.05 to 2.5 μg l− 1 As range using peak area as the analytical signal and maximum gain in the detector setting. A limit of detection (3σ) of 0.02 μg l− 1 and relative standard deviation values close to 2% for 10 independent measurements of a 1 μg l− 1 As solution were obtained. The sampling frequency increased from 45 to 102 h− 1 with the subsequent saving in carrier gas used and reduction in wastes generated. The instrumental modification, which could be used for other elements currently determined by atomic fluorescence spectrometry, will permit hydride generators of more reduced dimensions to be constructed.