Masato Aihara

Determination of rare earth elements in seawater by on-line column preconcentration inductively coupled plasma mass spectrometry.

A home made column of commercially available iminodiacetate resin, Muromac A-1 (50-100 mesh) was used to concentrate rare earth elements (REEs) (15 elements: Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in seawater. An automated low pressure flow analysis method with on-line column preconcentration/inductively coupled plasma mass spectrometry (ICP-MS) is described for the determination of REEs in seawater. Sample solutions (adjusted to pH of 3.0) passed through the column. After washing the column with water, the adsorbed elements were subsequently eluted into the plasma with 0.7 M nitric acid. Calibration curves were accomplished by means of purified artificial seawater with a sample loading time of 120 s. Detection limits (DLs) of the on-line column preconcentration/ICP-MS by eight replicate operations were between 0.040 and 0.251 pg ml(-1) for REEs in the artificial seawater. The precision was less than 8.9% for REEs and one sample can be processed in 7 min using a 7 ml of sample. The proposed method was applied to determine REEs in coastal seawater of Hiroshima Bay, Japan.

Determination of iron(II) and total iron in environmental water samples by flow injection analysis with column preconcentration of chelating resin functionalized with N-hydroxyethylethylenediamine ligands and chemiluminescence detection

A flow injection analysis (FIA) technique for the determination of Fe(II) and total-Fe in environmental water samples has been developed with a high sensitivity. The resin used for preconcentration of iron was the macroporous resin, Amberlite XAD-4 functionalized by N-hydroxyethylethylenediamine (HEED) groups. The technique employed was FIA by combination of on-line chelate resin preconcentration and chemiluminescence detection (CL), using brilliant sulfoflavine and hydrogen peroxide reagent solutions. The interference by coexisting Fe(III) could be eliminated by addition of 1x10(-6) mol of deferrioxamine B solution. The detection limits of Fe(II) and total-Fe were 0.80 and 0.36 nmol l(-1) for 5.6-ml seawater samples with a concentration of 2 nmol l(-1). The relative standard deviations for both samples were less than +/-4%. A typical analysis for Fe(II) can be performed in 7.5 min. The technique was ascertained by comparing the analytical value of total-Fe with the certified value of Fe in the reference standard seawater CASS-3.

Determination of chromium(III) and total chromium in seawater by on-line column preconcentration inductively coupled plasma mass spectrometry☆

Abstract An automated low-pressure flow injection method with on-line column preconcentration using inductively coupled plasma mass spectrometry is described for the determination of chromium(III) and total chromium in seawater. A home-made column of commercially available iminodiacetate resin, Muromac A-1, was used to concentrate chromium(III) in seawater at a pH of 3.0. Following washing of the column with water, the chromium(III) was eluted and transferred to the plasma with 0.70 M nitric acid. Total chromium was determined after the reduction of chromium(VI) to chromium(III) with a 2-mM hydroxylamine solution at pH 1.8. Detection limit (three times the relative standard deviation of the background) of chromium(III) in the artificial seawater based on eight replicate measurements was 0.020 ng ml −1 with a sample loading time of 120 s. The precision was ±1.9%. One sample can be processed in 5 min. Calibration was accomplished by means of artificial seawater. The proposed method was verified by the analysis of two Reference Standard Materials of seawater NASS-4 and CASS-3.

Mirror-Coated Long-Path Cells for Colorimetry with the Use of a Bifurcated Optical Guide

For sensitive measurement of the absorbance of aqueous solution, mirror-coated long-path cells have been constructed, in which introduction of light from a laser diode and collection of the reflected light passing through the analyte solution are done through the same end of the cells with the use of a bifurcated fiber. The absorbance of the solution has been enhanced about 20 to 30 times by using the present system. Also, the present mirror-coated long-path cells show a sharp response in turbidity with respect to the change toward smaller particle sizes in Latex gel. The present detection system has been coupled with the flow injection analysis of phosphate in molybdenum blue colorimetry. Detection of phosphate at 1 ng P/mL is possible with this measurement system—a result which is rather difficult to achieve with the use of a commercial auto-detection system.

Determination of tin in aluminium alloys by inductively coupled plasma atomic emission spectrometry after solvent extraction with potassium xanthate.

キサントゲン酸塩類を用いる微量スズの溶媒抽出/誘導結合プラズマ発光分析法について検討した。スズーキサントゲン酸錯体は酸性溶液中から抽出され,最適なpHは0。2～1.5であった。抽出試薬は,プロピルキサントゲン酸カリウムが0。06mol以上0.3molまで一定の抽出率を示して最適であった。また10・0,30.0および50.0μ9のスズをとり,それぞれ10回の定量をくり返した結果,相対標準偏差はL3～1.7%であり,定量精度は良好であった。本法でアルミニウム合金中のスズの定量を行った結果,分析値は保証値とよく一致しており,満足すべき結果が得られた。

Determination of gallium in aluminium alloys by ICP-AES after solvent extraction with potassium xanthate.

キサントゲン酸塩を用いる溶媒抽出/ICP-AESにより,アルミニウム合金中のガリウムの定量を行った.ガリウム-キサントゲン酸錯体は酸性溶液中から抽出され,最適なpHは0.5～2.0であった.抽出試薬はエチルキサントゲン酸カリウムが最適であり,抽出系への添加量は,0.2mol以上必要であった.又,5.0,10.0及び20.0μgのガリウムをとり,それぞれ10回の定量を繰り返して得られた相対標準偏差は1.1～2.0%であり,定量精度は良好であった.本法で実試料の分析を行い,参考値と比較したところ,満足すべき結果が得られた.