Figures of Merit and Fundamental Processes in the Analysis of Ca from Liquid Samples Using an r.f. CCP Torch with Tubular and Ring Electrodes

A radiofrequency capacitively coupled Ar plasma, obtained with a molybdenum tubular electrode placed inside a quartz tube and one or two copper ring electrodes placed outside the tube, was used as spectral source for determination of atoms, ions and molecular radicals of calcium. A simultaneous spectrometer equipped with a photodiode array was used for detection of emission spectra. The atomization and ionization processes of Ca species were studied in the presence and absence of NaCl and H3PO4 matrix, with both single ring and two rings electrode torches. The limits of detection are 250 ng mL–1 for CaII 393 nm, 100 ng mL–1 for CaI 423 nm, 230 and 100 ng mL–1 for CaOH 555 nm and 622 nm. The recovery degree for certified plasma serum samples was 99.4 ± 4.4% and the RSD was between 3.8–4.9%. For 5 blood samples the RSD of Ca content is 2.9–4.4%

Figures of Merit and Fundamental Processes in the Analysis of Ca from Liquid Samples Using an r.f. CCP Torch with Tubular and Ring Electrodes

A radiofrequency capacitively coupled Ar plasma, obtained with a molybdenum tubular electrode placed inside a quartz tube and one or two copper ring electrodes placed outside the tube, was used as spectral source for determination of atoms, ions and molecular radicals of calcium. A simultaneous spectrometer equipped with a photodiode array was used for detection of emission spectra. The atomization and ionization processes of Ca species were studied in the presence and absence of NaCl and H3PO4 matrix, with both single ring and two rings electrode torches. The limits of detection are 250 ng mL–1 for CaII 393 nm, 100 ng mL–1 for CaI 423 nm, 230 and 100 ng mL–1 for CaOH 555 nm and 622 nm. The recovery degree for certified plasma serum samples was 99.4 ± 4.4% and the RSD was between 3.8–4.9%. For 5 blood samples the RSD of Ca content is 2.9–4.4%

Traces of Cu, Mn and Zn in Aquatic Animals, Water and Sediments from the Cris River Basin West Romania. Part II: Distribution Study

The paper presents the determination of Cu, Mn and Zn (TRT r.f.CCP-AES, FAAS) in water, sediment and aquatic animals (fish fillet, freshwater molluscs gills and muscles) collected in the basin of the Cris rivers (White Cris and Black Cris) in West Romania. The concentrations in water were in the range: 1-15 pg Lr1 (Cu), 10-1500 pg L-1 (Mn), 3-100 pg L-1 (Zn). Metal contents, as dry mass fractions, w^m x IO6, were: 5-380 (Cu), 225-2000 (Mn), 23-1140 (Zn) in sediment; 1-11 (Cu), 4-40 (Mn), 8-130 (Zn) in fish fillet, and 5-34 (Cu), 100-600 (Mn) and 50-130 (Zn) in mollusc muscles with higher values for the White Cris samples. Among the seven sample collection sites only one was identified as having concentrations of Mn and Zn in water higher than the admitted levels, but the limits of tolerance for aquatic organisms were not exceeded in either river. In mollusc gills, the metal contents expressed as wdm x IO6 were: 8-60 (Cu), 11000-16000 (Mn), 190-1200 (Zn), and similar for both rivers in the case of Mn

Traces of Cu, Mn and Zn in Aquatic Animals and Sediments from the Cris River Basin West Romania. Part I: Statistical Evaluation of Data Obtained by Atomic Emission Spectrometry with Radiofrequency Capacitively Coupled Plasma Source and Flame Atomic Absorption Spectrometry

The limits of detection in r.f.CCP-AES were 2 (Cu), 6 (Mn) and 3 (Zn) pg g_1. Statistic evaluation of the results was based on 31 samples collected in the basin of the Cris rivers, Romania. After removing the samples with a metal concentration lower than the limit of determination in TRT r.f.CCP-AES, the F-test (95% confidence level) showed similar precision in the two methods, with one exception in the case of Mn and one in the case of Zn. From 21, 28 and 31 determinations of Cu, Mn and Zn, statistical correlation and regression as well as the analysis of Bland and Altman (95% confidence level) showed systematic errors in TRT r.f.CCP-AES versus FAAS only in one case for Cu, two cases for Mn and one case for Zn. The metal content amounted to: 10-400 pg g-1 (Cu), 20-16000 pg g-1 (Mn) and 20-1200 pg g-1 (Zn)