Assessing reference levels of nickel and chromium in cord blood, maternal blood and placenta specimens from Ankara, Turkey

Objective: Placenta is a temporary organ that connects the developing fetus and the mother. However, it cannot protect the embryo against chromium (Cr) and nickel (Ni) exposure. Quantification of Cr and Ni in biological and ecological subjects is challenging. Thus, the first goal of this study was to provide a validated Graphite Furnace Atomic Absorption Spectrometry (GFAAS) method to determine Cr and Ni in mothernewborn specimens. The second goal was to assess the reference Ni and Cr contents in cord blood, maternal blood, and placenta samples in a population from Ankara. Material and Methods: Biological samples were collected from 100 healthy mother-newborn pairs. Metal levels were quantified by GFAAS. Method validation of this toxicological analysis was performed by the use of certified reference materials, and assessed through accuracy, precision, specificity, range, quantitation, and detection limits. Results: Mean Cr levels of maternal blood, placentas, and cord blood were 0.337 +/- 0.222 mu g/L, 0.221 +/- 0.160 mu g/kg, 0.121 +/- 0.096 mu g/L, respectively while mean Ni concentrations were 0.128 +/- 0.093 mu g/L, 0.124 +/- 0.067 mu g/kg, 0.099 +/- 0.067 mu g/L, respectively. The method showed linearity with excellent correlation coefficients (r(2)) for Cr (0.9994) and Ni (0.9999). Satisfactory recovery and coefficient of variation for Cr and Ni were 102.85% and 102.35%; 1.75% and 2.91%, respectively. Relative error did not exceed 3%, demonstrating the accuracy of the method. Control charts were drawn to assess inter-day stability. The predicted reference ranges for Cr and Ni concentrations in maternal blood, placenta and cord blood were: Cr 0.033-0.75 mu g/ L; 0.032-0.526 mu g/kg; 0.031-0.309 mu g/L and for Ni were 0.011-0.308 mu g/L; 0.024-0.251 mu g/kg; 0.066-0.209 mu g/L, respectively. Conclusion: The reported reference values of biological specimens in this paper will provide complementary aid to health professionals in terms of assessment of environmental and occupational exposure.

Automated summary

The study aimed to validate a GFAAS method for quantifying Cr and Ni in mother-newborn specimens and to assess the reference Ni and Cr contents in cord blood, maternal blood, and placenta samples in a population from Ankara. The results showed satisfactory recovery, accuracy, and precision of the method, providing reference values for future health assessments related to environmental and occupational exposure.