During the analysis, sample preparation was carried out using European method EN 71, Part 3, specifying extraction of sample by hydrochloric acid for 2 hours at 37 ˚C in darkness followed by colorimetric determination of hexavalent chromium by 1,5-diphenylcarbazide reagent.
Determination of hexavalent chromium in toys by using UV/Vis Spectrometry
Toy safety is a joint responsibility among governments, the toy industries, regulatory bodies and parents. The toy safety regulations are intended to reduce potential risks children could be exposed to when playing with toys. Enforcement of the regulations aims to identify those toys that do not comply with the legislation and remove them from the market. The toxic elements that may be present in toys are heavy metals such as antimony, arsenic, chromium, lead, mercury, etc., which can accumulate in the body and may cause adverse effects. Therefore, analysis of such elements is important to ensure safety. The European standard EN 71 specifies safety requirements for toys. EN 71, Part 3 contains one section entitled “Migration of certain elements”. In this section it defines the limits for element migration from toy materials including hexavalent chromium. In EN 71, Part 3, the limit specified for migration of chromium is not more than 60 mg/kg. In the environment, chromium is found in several different forms including two oxidation states as trivalent i.e., Cr(III) and hexavalent i.e., Cr(VI). Cr(III) is considered to be an essential nutrient for the body. In contrast Cr(VI) is relatively mobile in the environment and is acutely toxic and carcinogenic. It is widely used in electroplating, stainless steel production, leather tanning, paint, and textile manufacturing.