Disposable commercial CI8 mini-cartridges are treated with tributyltin chloride (TBTCI) and used for selective pre-concentration of Crvl from aqueous solutions. The accumulated Crvl -TBTCI adduct is eluted with 5 ml of methanol and measured using electrothermal atomic absorption spectrometry. Pre-concentration factors of 100-fold are readily achieved for 0.100 ng ml-1 samples of CrVl with an average recovery of 98 k 8%.

No abstract

A simple, rapid and selective method for the determination of Crlll and Crvl in natural waters by ion-pairing high-performance liquid chromatography (HPLC) with flame atomic absorption spectrometry (FAAS) as the method of detection is described. The samples and standards are acidified with glacial acetic acid to a pH of 3.1-3.2. The eluent consists of dilute tetrabutylammonium phosphate also acidified to a pH of 3.1-3.2.Separation is accomplished on a 4 cm long column packed with polymeric CI8 material. The effluent from the column is fed directly into the atomic absorption spectrometer.Chromium(V1) added to pond water began to decay to CrIll immediately upon addition. The rate of decay depended on the level of suspended organic material in the water. The recovery of the sum of both Ct -111 and CrVl species in 65 spiked water samples was 100.9% with a standard deviation of 6.Z0/&.

No abstract

Excitation conditions for the green HPO bands, the uv PO bands, and the violet S(2) bands were explored. A cylindrical glass shield placed around the tip of a Beckman (sprayer) burner provided a simple arrangement to isolate a fuel rich environment of a reversed air-hydrogen flame. Samples were converted to aerosol in a separate nebulization chamber. The HPO band at 5262 A gave a detection limit of 6 microg/ml; the S(2) band, 5 microg/ml. Owing to low flame noise, both detection limits could be improved with interference filters in place of the Beckman small quartz monochromator. The PO bands are emitted best from fuel rich oxygen-acetylene flames with the normal Beckman sprayer burner. The significant aspect of this study lies in the introduction of liquid samples and circumvention of lengthy, and often uncertain, decomposition steps when handling many types of organic and biochemical compounds containing phosphorus and sulfur.