摘要
In this study,seven pretreatment methods for chromium speciation in tanned leather were evaluated:acidic miner‑alization,ethylenediaminetetraacetic acid(EDTA)extraction,diethylenetriaminepentaacetic acid(DTPA)extraction,alkaline extraction(NH 4 OH),ammonium nitrate extraction(NH 4 NO 3),water extraction,and phosphate buffer extrac‑tion.Acidic mineralization permitted the decomposition of the organic matter and ensured the complete digestion of leathers,giving access to the total content of chromium in each sample using inductively coupled plasma‑atomic emission spectrometry(ICP‑AES).From all the extractant media tested,EDTA proved to be the most efficient,allowing the extraction of Cr(VI)and Cr(III)as a Cr(III)‑EDTA complex,quantitatively.Method validation is presented for EDTA extraction and direct mineralization.For the EDTA extraction,method detection limit(MDL)and method quantifica‑tion limit(MQL)for total Cr in leather were 3.4 ppb and 11.2 ppb(µg of total Cr per L of extraction solution),respec‑tively.Due to the lack of leather certified reference materials(CRMs)for Cr(VI),accuracy was evaluated by spiking leather samples with a Cr(VI)solution.The spike recovery of EDTA microwave assisted extraction ranged from 91.0 to 108.6%.Interday precision was also evaluated and all variation coefficients were below 5%,for both mineralization and EDTA extraction.This article provides an efficient procedure to extract quantitatively chromium from leather,while maintaining the speciation,which can be further followed by ion chromatography‑inductively coupled plasma‑mass spectrometry(IC‑ICP‑MS).
基金
This work has been partially supported by University of Rouen Normandy,INSA Rouen Normandy,the Centre National de la Recherche Scientifique(CNRS),European Regional Development Fund(ERDF)NºHN0001343,Labex SynOrg(ANR‑11‑LABX‑0029)
Carnot Institute I2C,the graduate school for research XL‑Chem(ANR‑18‑EURE‑0020 XL CHEM)
Region Normandie,and Consejo Nacional de Ciencia y Tecnologia(CONACYT CVU 707668)
IC instrument has been financed by RIN LabEx Milliflux Nº19E00566 and ICP/MS through Bioenairgy project(FEDER NºHN0001343).