Determination of Cadmium in River Water by Electrothermal Atomic Absorption Spectrometry after Internal Standardization-Assisted Rapid Coprecipitation with Lanthanum Phosphate

Abstract

Cadmium ranging from 1 -8 ng could be coprecipitated quantitatively with lanthanum phosphate at pH 5 -6 from up to 200 mL of river water samples spiked with 5 µg of indium as an internal standard. Cadmium and indium coprecipitated were measured by using electrothermal atomic absorption spectrometry. The cadmium content in the original sample solution could be determined by internal standardization with indium. Since complete collection of the precipitate and strict adjustment of the volume of the final solution after coprecipitation are not required in this method, the precipitate could be collected by using decantation and centrifugation, and then dissolved with 1 mL of about 2.4 mol L -1 nitric acid. The proposed method is simple and rapid, and enrichment close to 200-times can be attained; the detection limit (3σ, n = 6) was 0.63 ng L -1 in 200 mL of the sample solution.

Determination of Heavy Metals at Sub-ppm Levels in Seawater and Dialysis Solutions by FA AS after Tetrakis(pyridine)-nickel(II)bis(thiocyanate) Coprecipitation

“…In many cases, the usage of a separation and/or preconcentration method is required prior to analysis of the samples in order to improve the sensitivity and accuracy of atomic spectrometric techniques. For this purpose, solvent extraction, 1 ion-exchange, 2,3 electrolytic deposition, 4 vaporization, 5 solid-phase extraction, 6,7 and coprecipitation with phosphates, [8][9][10][11] hydroxides, [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] various dithiocarbamates, [28][29][30][31][32][33] have been proposed for preconcentration and separation of analyte ions from various matrix media. Döner and Ege 34 have investigated for the determination of copper, cadmium and lead in aqueous solutions by flame atomic absorption spectrometry after coprecipitating with aluminum hydroxide.…”

Use of Yttrium Phosphate as a Coprecipitant for Separation/Concentration of Lanthanoids

“…Then, the application of the rapid coprecipitation technique 19,21,[25][26][27][28][29] to the coprecipitation using yttrium phosphate was investigated to make the operation in the coprecipitation simple and rapid. In the rapid coprecipitation technique, the amount of carrier or internal standard element in the final solution after coprecipitation must be measured because the ratio of the remaining amount of the carrier or internal standard element in the solution after coprecipitation to the added amount of it in the initial sample solution is required for element determination.…”

“…We have studied the coprecipitation of elements with metal phosphates, and have also applied the coprecipitation method to the separation/concentration of elements, including Pb, [14][15][16][17][18][19][20][21] Sn(IV), 22 In, 23 Cr(III), 24 Fe(III), 15,20,21 Bi, 15 and Cd, 25 for their atomic spectroscopic determination.…”

“…To alleviate this point, a rapid coprecipitation technique has been proposed. 19,21,[25][26][27][28][29] In this technique, complete separation of the precipitate is not necessary because the amount of the desired element in the sample solution is determined based on the ratio of the remaining amount of the carrier or internal standard element in the solution after coprecipitation to the added amount of it in the sample solution. In this work, we also succeeded to apply this technique to coprecipitation using yttrium phosphate; the operation in the proposed coprecipitation method is quite simple and rapid.…”

Large-Volume Injection Electrothermal AAS Combined with Tungsten-treated Pyrolytic Graphite Furnace: Determination of Cadmium in Tap, Snow and River Water Samples with Phosphate Modifier

“…[13][14][15] The 111 Cd concentration was reported to be in the range of 53 -201 ng l -1 in collected snow at the top of, or near the top of, mountains in North Japan. 16 Recently, Kagaya et al 17 repoted that an indium internal standard-assisted rapid coprecipitation with lanthanum phosphate was applied to the determination of Cd in river water. A LOD value of 0.63 ng l -1 in 200 ml of sample solution was observed with an enrichment factor of 200 times.…”