Application of pneumatic flow injection-tandem spectrometer system for chromium speciation.

In this approach, a pneumatic flow injection-tandem spectrometer system, without a delivery pump, has been developed to study chromium speciation. In this system, suction force of pneumatic nebulizer of a flame atomic absorption spectrometer has been used for solution delivery through the manifold. Cr(VI) and total Cr concentrations were determined using UV-Vis and FAAS spectrometers, respectively. The Cr(III) was determined by difference. The calibration curves were linear up to 10 mug mL-1 and 20 mug mL-1 for Cr(VI) and total Cr with detection limit of 0.12 mug mL-1 and 0.07 mug mL-1 for Cr(VI) and Cr(III), respectively. The midrange precision and accuracy are less than 1.98% and +/- 2.50% for two species, respectively, at a sampling rate of 100 h-1. This system was applied for the determination of the chromium species in spiked and natural waters as well as industrial waters.