An ICP-MS Study for Quantitation of Nickel and Other Inorganic Elements in Urine Samples: Correlation of Patch Test Results with Lifestyle Habits.

Nickel (Ni) is a frequently used metal in the production of many products, and Ni exposure occurs in humans through food, inhalation, and skin. Studies reported Ni as the most common allergen diagnosed in the serial patch test. The main purpose of our study was to determine the concentration of Ni and other elements in the urine samples of individuals with Ni-sensitivity and to determine the effect of lifestyle habits on these variables. This study was conducted with 388 participants; additionally, both Ni patch test and inorganic analysis (for 24 elements) method in urine with inductively coupled plasma-mass spectrometry (ICP-MS) were applied to all participants. Ninety-two (23.7%) of the participants were found to have nickel sensitivity with a mean urine concentration of 4.475 μg/g creatinine (median=4.260; SD=2.527). The urine nickel concentration was significantly different between female and male participants (p =0.001). We found a significant correlation between Ni and other metals alongside various element pairs. The mean urine Ni concentration of the individuals with a positive Ni sensitivity test result was not different from that of the participants without Ni sensitivity (4.475 vs 4.256 μg/g creatinine, respectively; p = 0.068). The high accuracy, recovery, and repeatability data obtained from the analyses indicate that this study is efficient and appropriate for the quantitative determination of nickel and other elements in urine samples. Ni-containing objects and Ni-rich foods should be of concern for individuals with hypersensitivity reactions to the element.