Abstract: Metal alkoxide glass immobilized 8-quinolinole (MAF-8HQ) was synthesized from the solutions for the resin for analysis of ultra trace level iron determination in seawater by Nakayama and Obata. Since the blank values of trace metals in the resin are very low, the resin was applied for the determination of trace metals in seawater. A home made column of MAF-8HQ was used to separate and concentrate trace metals (V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb and U) from seawater. An automated low pressure flow analysis method with on-line column pre-concentration/inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of trace metals in seawater. Sample solutions (adjusted to pH 5.5) were passed through the column. After washing the column with water, the adsorbed metals were subsequently eluted into the plasma with 0.7 M nitric acid. Detection limits (DLs) of the trace metals in the artificial seawater were 0.008 ng mL-1 for V, 0.004 ng mL-1 for Mn, 0.004 ng mL-1 for Co, 0.014 ng mL-1 for Ni, 0.014 ng mL-1 for Cu, 0.050 ng mL-1 for Zn, 0.002 ng mL-1 for Mo, 0.003 ng mL-1 for Cd, 0.017 ng mL-1 for Pb and 0.001 ng mL-1 for U, respectively, as the concentrations of analyte metals corresponding to three times (3s) the standard deviation of blank signal intensities by 10 replicate measurements. By using 120 s of sample loading times, 40-66-fold enrichment factors were obtained for V, Co, Cu, Zn, Cd, Pb and U. One sample can be processed in 7 mL and 7 min. The proposed method was verified by the analysis of trace metals in the two certified reference materials (CRMs) of seawater CASS-4 and NASS-5.

Abstract: In this study, a new technique by hydride generation-atomic fluorescence spectrometry (HG-AFS) for determination and speciation of inorganic arsenic using multisyringe flow injection analysis (MSFIA) is reported. The hydride (arsine) was generated by injecting precise known volumes of sample, a reducing sodium tetrahydroborate solution (0.2%), hydrochloric acid (6 M) and a pre-reducing solution (potassium iodide 10% and ascorbic acid 0.2%) to the system using a multisyringe burette coupled with one multi-port selection valve. This solution is used to pre-reduce As(V) to As(III), when the task is to speciate As(III) and As(V). As(V) is determined by the difference between total inorganic arsenic and As(III). The reagents are dispensed into a gas-liquid separation cell. An argon flow delivers the arsine into the flame of an atomic fluorescence spectrometer. A hydrogen flow has been used to support the flame. Nitrogen has been employed as a drier gas (Fig. 1). Several variables such as sample and reagents volumes, flow rates and reagent concentrations were investigated in detail. A linear calibration graph was obtained for arsenic determination between 0.1 and 3 µg l-;1. The detection limit of the proposed technique (3sb/S) was 0.05 µg l-;1. The relative standard deviation (RSD) of As at 1 µg l-;1 was 4.4 % (n = 15). A sample throughput of 10 samples per hour was achieved. This technique was validated by means of reference solid and water materials with good agreement with the certified values. Satisfactory results for speciation of As(III) and As(V) by means of the developed technique were obtained.