Determination of trace metals in vegetables and water samples using dispersive ultrasound-assisted cloud point-dispersive µ-solid phase extraction coupled with inductively coupled plasma optical emission spectrometry

Luthando Nyaba; Philiswa N Nomngongo

doi:10.1016/j.foodchem.2020.126749

Determination of trace metals in vegetables and water samples using dispersive ultrasound-assisted cloud point-dispersive µ-solid phase extraction coupled with inductively coupled plasma optical emission spectrometry

Food Chem. 2020 Aug 30:322:126749. doi: 10.1016/j.foodchem.2020.126749. Epub 2020 Apr 4.

Authors

Luthando Nyaba¹, Philiswa N Nomngongo²

Affiliations

¹ Department of Chemical Sciences, University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Doornfontein 2028, South Africa; DSI/NRF SARChI Chair: Nanotechnology for Water, University of Johannesburg, Doornfontein 2028, South Africa.
² Department of Chemical Sciences, University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Doornfontein 2028, South Africa; DSI/NRF SARChI Chair: Nanotechnology for Water, University of Johannesburg, Doornfontein 2028, South Africa; DSI/Mintek Nanotechnology Innovation Centre, University of Johannesburg, Doornfontein 2028, South Africa. Electronic address: pnnomngongo@uj.ac.za.

PMID: 32283371
DOI: 10.1016/j.foodchem.2020.126749

Abstract

A simple method combining ultrasound assisted cloud point extraction (UA-CPE) and dispersive μ-solid phase extraction (D-μ-SPE) was developed for preconcentration of As, Cd, Cr, Co, Sb, Pb and Tl to inductively coupled plasma optical emission spectrometric (ICP-OES). At optimum conditions, the linearity, limits of detection and limits of quantification were 0.20-1000 µg L^-1, 90-150 ng L^-1 and 200-500 ng L^-1, respectively. The intraday (n = 20) and intraday (n = 5) precisions reported as the relative standard deviation ranged from 1.5 to 3.5% and 1.9-4.5%. The trueness of the method was investigated using CRM BCR679, NIST SRM 1573a, and SRM 1640a, as well as spiked recovery experiments. Satisfactory recoveries and relative errors ranging from 97 to 99.3% and -4.0 to 2.4% were obtained. The proposed UA-CPE-D-µ-SPE/ICP-OES method was successfully applied for various real samples such as groundwater, bottled mineral water, river water and borehole water and food samples.

Keywords: Dispersive µ-solid phase extraction response surface methodology; Environmental and food matrices; Layered double hydroxide nanocomposite; Trace metals; Ultrasound-assisted cloud point; Vegetables.

MeSH terms

Drinking Water / analysis
Fresh Water / analysis*
Limit of Detection
Nanotubes, Carbon / chemistry
Solid Phase Microextraction / methods*
Sonication
Spectrophotometry / methods*
Trace Elements / analysis*
Trace Elements / isolation & purification
Vegetables / chemistry*
Vegetables / metabolism

Substances

Drinking Water
Nanotubes, Carbon
Trace Elements