Atomic absorption determination of copper in silicate rocks by continuous precipitation preconcentration

Abstract

A selective atomic absorption spectrophotometrlc method has been developed for the preconcentration and determination of copper after continuous precipitation with rubeanlc acid. The precipitate Is separated by continuous filtration and dissolved In potassium dlchromate. A concentration factor of up to 500 is achieved. Several calibration graphs are used for the determination of copper(II) In the range 0.3-200 ng/mL with a sampling frequency between 1 and 20 h~1 and a relative standard deviation between 1.4 and 3.0%. The proposed method has been successfully applied to determination of copper at the /tg/g level In silicate rocks.

Biosorption and preconcentration of lead and cadmium on waste Chinese herb Pang Da Hai

“…Therefore, sample preconcentration is becoming an essential treatment step before flame atomic absorption determination. For this purpose, there are many methods have been developed, including liquid-liquid extraction [1,2], coprecipitation [3][4][5], ion-exchange [6,7], chelating resins [8][9][10][11][12] and solid-phase extraction [13]. These methods have advantages of high selectivity, sensitivity and fast speed of operation, but they have also obvious disadvantages of their high cost and causing second pollution to the environment.…”

Atomic spectrometric detectors for flow-injection analysis

“…Lead [91] have been determined in tap water by precipitation with hydroxide ion; copper [92] and cobalt [93] have been determined in rocks by precipitation with organic precipitants. For copper the reagent was dithiooxamide with dissolution in a solution of potassium dichromate in nitric acid.…”

“…For copper the reagent was dithiooxamide with dissolution in a solution of potassium dichromate in nitric acid. Both stainless-steel [90,92,93] and disposable nylon membrane filters [94] have been used. An interest ing feature of this approach is that other matrix components, which could compete with analyte species for binding sites on a solid extractant, may help improve precipitation collection efficiencies by means of coprecipitation.…”

Copper(II)–rubeanic acid coprecipitation system for separation–preconcentration of trace metal ions in environmental samples for their flame atomic absorption spectrometric determinations

“…Rubeanic acid has been used for preconcentration and determination of some metal ion from various media [39][40][41][42].…”