The ISO 17075-2 Standard was published in 2017. In this standard appeared for the first time the determination of hexavalent chromium in leather by liquid chromatography. Two alternative instrumental options are proposed in this method: the direct determination of the absorbance of the chromate peak (Annex B of the Standard) or after the post-column derivatisation with diphenylcarbazide (Annex C). Instrumental performance parameters and economic costs between both methods are compared in this paper. One hundred different leathers were analysed by both chromatographic systems. The two methods proved very good correlation. The post-column method has a higher instrumental sensitivity compared to the direct detection method, which is important to reduce the uncertainty of the measure in samples around the 3mg/kg current regulatory limit. Other important advantages are its absolute selectivity, which allows the secure identification of the hexavalent chromium in all type of complicated matrixes, and the higher durability of its well protected columns due to the use of cost-effective guard columns. Due to the technical advantages and the slight difference in the equipment cost, which can be compensated thanks to the larger lifespan of the chromatographic columns, it is concluded that the post-column method is the most suitable option for the most determination of hexavalent chromium in leather.
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