[Validation of an analytical methodology to determine polychlorinated biphenyls in samples from blood plasma]

Introduction: Polychlorinated biphenyls are among the five most toxic persistent contaminants for living organisms according to the Agency for Toxic Substances and Disease Registry (ATSDR).

Objective: To standardize and validate an analytical method to determine and quantify polychlorinated biphenyl indicators in samples from blood plasma by means of gas chromatography-mass spectrometry.

Materials and methods: We fortified a plasma pool to do the matrix assays. Additionally, we used the NIST SRM® 1958 reference material for the veracity and intermediate accuracy assays.

Results: Methodology recovery percentages ranged between 88.4 and 97.5%, and the bias was less than 20%. Detection and quantification limits were 0.04 μg/L and 0.10 μg/L, respectively, for all polychlorinated biphenyl indicators. The linearity represented by the determination coefficient (R2) varied between 0.9866 and 0.9886. Accuracy, expressed as relative standard deviation was less than 20% in all the linear work range (0.5-500 μg/L). Finally, we analyzed 115 samples from Colombian population in various zones of the country and we found 65 positive samples, from which two samples were above HBM-II (7.0 μg/L, 2XΣPCB 138, 153, 180), and two, above HBM-I (3.5 μg/L, 2XΣPCB 138, 153, 180).

Conclusion: The method we developed is accurate for PCB analysis in blood plasma samples and could be used for biological surveillance of these contaminants in the Colombian population.