Optimization of Sample Preparation Procedure for Evaluation of Occupational and Environmental Exposure to Nickel

Abstract: Nickel is an important constituents widely used in different industrial processes for production of various syn thetic materials. For evaluation of workers’ exposure to trace toxic metal of Ni (II), environmental and biological monitor ing are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone as pects prior to analysis. To evaluate factors influencing quantitative analysis scheme of nickel, solid phase extraction using mini columns filled with XAD-2 resin was optimized with regard to sample pH, ligand concentration, loading flow rate, elution solvent, sam ple volume (up to 500 ml), elution volume, amount of resins, and sample matrix interferences. Nickel ion was retained on solid sorbent and was eluted with followed by simple determination of analytes by using flame atomic absorption spectrome tery. Obtained recoveries of metal ion were more than 92%. The amount of the analyte detected after simultaneous pre-concen tration was basically in agreement with the added amounts. The optimized procedure was also validated with three differ ent pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. The developed method promised to be applicable for evaluation of other metal ions present in different environ mental and occupational samples as suitable results were obtained for relative standard deviation (less than 10%). This optimized method can be considered to be successful in simplifying sample preparation for trace residue analy sis of Ni in different matrices for evaluation of both occupational and environmental exposures.