Spectrophotometric Determination of Iron on Skin of Hand Palm with 2,4,6-(2′-Pyridyl)-1,3,5-Triazine as Chromogenic Reagent

Based on the color reaction of Fe(Ⅱ) with 2,4,6-(2′-pyridyl)-1,3,5-triazine (TPTZ) as chromogenic reagent, a spectrophotometric method for determination of iron contaminated on skin of hand palm was proposed. Imprint of iron ware on the palm skin was collected by wiping with absorbent cotton wetted previously in deionized water, and the liquid contained in the cotton was squeezed out and recieved into a 25 mL volumetric flask. The collection was repeated once more. The color reaction was carried out by addition of 30 g·L-1 ascorbic acid solution (2 mL), 1 g·L-1 TPTZ solution (2 mL) and pH 4.2 NH4OAc buffer solution (3 mL) in succession. After diluting to 25 mL and standing for 10 min, its absorbance was measured at 596 nm. Beer′s law was obeyed in the range within 2.0 mg·L-1. It was shown that upon grasping iron ware in one′s palm, amount of iron on the palm skin increases with the increase of grasping time, and higher the humidity of palm skin, higher will be the amount of iron contaminated. A difference of 12 μg of iron was found between the maximum and mininum values.