Flame atomic absorption spectrometric determination of lead in waste water and effluent after preconcentration using a rapid coprecipitation technique with gallium phosphate

Abstract

A determination method for lead in waste water and effluent was studied using flame atomic absorption spectrometry after preconcentration of lead by the rapid coprecipitation technique with gallium phosphate. Lead ranging from 0.5 to 50 microg was quantitatively coprecipitated with gallium phosphate from 100-150 mL sample solution (pH approximately 5). The presence of gallium phosphate did not affect the atomic absorbance of lead. Since the concentration of gallium in the final sample solution is also measurable by flame atomic absorption spectrometry at 250.0 nm without further dilution, the rapid coprecipitation technique, which does not require complete collection of the precipitate, becomes possible using a known amount of gallium and measuring the concentrations of both lead and gallium in the final sample solution by flame atomic absorption spectrometry. The 32 diverse ions tested gave no significant interferences in the lead determination. The method proposed here is rapid and has good reproducibility.

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.…”

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

“…For dissolution of the precipitate, nitric acid was chosen because of the small influence on the atomic absorbance of cadmium; 2 almost a constant atomic absorbance was obtained over a wide acid-concentration range of 0.8 -3.2 mol L -1 in the final solution. A centrifugation using a 50 mL centrifuge tube or a Nalgene 175 mL polystyrene conical centrifuge bottle at 3500 rpm for 10 min was conveniently utilized for collecting the precipitate 17,18 after the supernatant solution was discarded by decantation.…”

“…We have proposed a rapid coprecipitation technique [15][16][17][18] to simplify the operation in coprecipitation. In this technique, a known amount of the carrier element is used for the coprecipitation of the desired metal; the amounts of the coprecipitated metal and the carrier element in the final solution are then determined.…”

Application of Internal Standardization to Rapid Coprecipitation Technique Using Lanthanum Phosphate for Flame Atomic Absorption Spectrometric Determination of Iron and Lead

“…1,2 However, the coprecipitation is sometimes troublesome and time-consuming during filtration, which is frequently used for collection of precipitate. Some techniques such as flotation 2 have been used to alleviate the weak points; a rapid coprecipitation technique [3][4][5] is also one of the most useful ways. We have suggested that gallium phosphate is an excellent coprecipitant for the rapid coprecipitation technique prior to flame atomic absorption spectrometric determination of lead.…”

“…We have suggested that gallium phosphate is an excellent coprecipitant for the rapid coprecipitation technique prior to flame atomic absorption spectrometric determination of lead. 5 In this method, a known amount of gallium (Ga0 mg) is added to the initial sample solution and concentrations of both lead coprecipitated (Pb1 µg mL -1 ) and gallium (Ga1 mg mL -1 ) in the final sample solution after the coprecipitation are measured. The lead content (Pb0 µg) in the original sample solution can be calculated by following equation: Pb0 = (Pb1/Ga1) × Ga0.…”