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Volatile species of Ag, Au, Cu, Zn, Cd, and As were generated at room temperature by the addition of sodium tetrahydroborate(III) to an acidified solution of the analytes. The vapor-phase species were rapidly transported to a heated quartz tube atomizer (QTA) for detection by atomic absorption spectrometry. A univariate approach was used to achieve optimized conditions and derive analytical figures of merit. The analytes are released from solution as molecular species (likely as metal hydrides) and are (partially) atomized in the QTA under nonoptimized conditions. Detection limits range from 1.8 (Zn) to 420 ng (Au). The efficiency of the generation process is estimated to be 92 +/- 4% for Au. Loss of analyte during transport to the QTA was minimized through use of the minimum length of narrow-bore Teflon transfer line possible.

A quantitative method based on FTIR has been developed to determine carbonate in synthetic apatites. The method measures the evolved CO2 after reaction of 50 mg apatite with 2 mL of hydrochloric acid (0.5 M) in a reaction vessel, heated to 40 degrees C. The CO2 evolved was swept by a carrier of nitrogen to a laboratory-made infrared gas cell of 39 mm pathlength and 490 microL volume. The signals were recorded as a function of time and the areas of the chemigram peaks obtained from the measurements in the wavenumber range of 2,500-2,150 cm(-1), were interpolated using a calibration curve. The method can be used to study apatites with carbonate contents below 0.2% with a sampling frequency of 8 h(-1).

The determination of Cd in whole blood and urine by electrothermal atomic absorption spectrometry using Pd-based modifiers and in situ decontamination was studied. The performance of Pd, Pd + NH4NO3, and Pd + Mg(NO3)2 as modifiers were compared with respect to maximum pyrolysis and atomization temperatures, background attenuation, linear calibration range and matrix interference. Samples were diluted (1 + 4) with 0.1% Triton X-100 (blood) or 0.2% HNO3 (urine), and introduced onto the graphite tube platform already containing the in situ dried and decontaminated modifier. The influence of modifier volume and concentration, as well as that of the dilution ratio was investigated. The proposed procedure involves the use of Pd(NO3)2 + (Mg(NO3)2 as modifier, a pyrolysis temperature of 700 degree C and an in situ decontamination step of 1200 degrees C. The atomization temperature was 1700 degrees C. The detection limit (n = 10, k = 3) was 0.22 micrograms l-1 for both samples. Typical relative standard deviation values (n = 3) were below 3%. Using matrix-matched standards, good agreement was observed between experimental and reference values in the analysis of certified reference materials. Interlaboratory comparison data have confirmed the validity of the proposed analytical procedure.