A simple, fast method is described for the determination of Ag, As, Cd, Cu, Cr, Fe, Ni, and Se in marine biological tissues by electrothermal atomic-absorption spectrometry (ETAAS) and Na, Ca, K, Mg, Fe, Cu, and Mn by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Solubilization of the biological tissue was achieved by using formic acid with vortex mixing followed by heating to 50 degrees C in an ultrasonic bath. Once solubilized, the tissues were diluted to an appropriate volume with water for analysis. Aliquots were sampled into a graphite furnace and ICP-AES using a conventional autosampler. The method was validated by use of biological certified reference materials from NRC, DORM-2, DOLT-2, DOLT-3, LUTS-1, TORT-2, and NIST SRMs 1566b and 2976. Simplicity and reduced sample-preparation time prove to be the major advantages to the technique.

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A spectrophotometric method is described regarding the determination of germanium. A colored complex of germanium with pheny fluorone was collected on an organic solvent-soluble membrane filter made of cellulose nitrate. The complex, together with the filter, was dissolved into N,IV dimethylformamide (3 cm3), and the absorbance of the solution was measured. The obtained calibration curve was linear from 0.05 to 1.0 µg of germanium and the molar absorption coefficient was 1.9x 105 dm3 mo -' cm-'. The relative standard deviation of the absorbance obtained at 1.0 µg of germanium was 0.4% ( n=11). The interference of molybdenum(VI) could be eliminated by hydrogen peroxide. The time required for one run was about ten minutes and germanium at 1 µg dm-3 levels could be easily determined. This method has been applied to the determination of germanium in samples of hot-spring water.

A highly sensitive, rapid and facile method of fluorophotometry is described for the determination of phosphate using the ion pair formation of molybdophosphate with Rhodamine 6G. This ion pair is collected on a membrane filter made of cellulose nitrate when the sample solution is adjusted to 0.35 mol dm-3 in sulfuric acid, 1.9 mmol dm-3 in ammonium molybdate and 3.1 µmol dm-3 in Rhodamine 6G, and it is filtered through the membrane filter under suction. The membrane filter together with the ion pair is dissolved into Methyl Cellosolve. The fluorescence intensity of this solution is measured at 555 nm with the excitation at 535 nm. The calibration curve of phosphate is linear from 5 to 100 ng of phosphorus, with the correlation coefficient of 0.999; the relative standard deviation was 1.6% for 100 ng of phosphorus (n=12). Although arsenic(V) causes positive error, no ions, including silicate, commonly existing in natural water interfere with the determination of phosphate. The proposed method was applied to the determination of phosphate-phosphorus in water samples and satisfactory results were obtained.