Simultaneous determination of nickel, lead, zinc, and copper in citrus leaves and rice flour by liquid chromatography with hexamethylenedithiocarbamate extraction

Abstract

8) Tanaka, M.; Kawaguchi, Y.; Nakae, M.; Mlzobuchi, Y.; Shono, T. J . Chromatogr. 1984, 299, 341-350. (9) Tanaka, M.; Kawaguchi, Y.; Shono, T.; Uebori, M.; Kuge, Y. Reversed-phase llquld chromatography followed by solvent extraction with hexamethyleneammonlum hexamethylenedlthlocarbamate (HMA-HMDC) was carrkd out to determlne NI, Pb, Zn, and Cu In standard reference citrus leaves and rice flour. These samples (250 mg) were ashed wlth nltrlc acid and perchloric acid. The metals In the ash were extracted into chloroform as HMDC chelates which were then separated on a C 18 column and rnonltored at 260 nm. This method permitted Separation and determlnatlon of Cd-, NI-, Pb-, Zn-, Cu-, Hg-, Co-, and BI-HMDC chelates. Cd, Hg, Co, and BI could not be detected, but the microgram per gram levels of NI, Pb, Zn, and Cu In the standard blologlcal materials were simultaneously determined wlthln 25 min.

Determination of Cadmium, Zinc, Nickel and Cobalt in Tobacco by Reversed-Phase High-Performance Liquid Chromatography with 2-(8-Quinolylazo)-4,5-diphenylimidazole as a Chelating Reagent

“…It has been used as a powerful technique for the simultaneous determination of metal ions. 14,15 This method shows the advantages of low cost, excellent selectivity and sensitivity; several groups of ligands such as azo compounds, 16,17 oxine and its derivatives 18,19 and dithiocarbamic acid 20,21 were used as derivatizing agents for the RP-HPLC determination of various metal ions.…”

Ultra-trace monitoring of copper in environmental and biological samples by inductively coupled plasma atomic emission spectrometry after separation and preconcentration by using octadecyl silica membrane disks modified by a new schiff's base

“…The procedure used for the extraction of these ions from tea sample was similar to that reported in the literature 28 . 10 mg of the dry tea sample (dried at 110 o C) was placed in a 50-mL beaker, followed by the addition of 7 mL of concentrated nitric acid, and the beaker was covered with a glass watch.…”

A novel method for fast enrichment and monitoring of hexavalent and trivalent chromium at the ppt level with modified silica MCM-41 and its determination by inductively coupled plasma optical emission spectrometry

“…The procedure used for the extraction of cations from samples was similar to that reported in the literature 27 . 100 mg of dry sample (dried at 110 o C) was placed in a 50 mL beaker, followed by the addition of 7 mL of concentrated nitric acid, and the beaker was covered with a glass watch.…”