Bisphenol A background contamination encountered during advanced blood sampling and laboratory analysis

ABSTRACT

Potential sources of a specific and considerable contamination with bisphenol A (BPA) via biological sample testing were investigated. Determination of BPA in animal plasma, collected in a commercially provided vacuum tube, revealed a significant contamination of 6 ng/ml of BPA in the tested sample, while blood serum from the same animal collected in a glass tube contained 0.37 ng/ml of BPA. Further investigation proved that the origin of the contamination was the separator gel in the vacuum collection tube, which contained, without any declaration from the producer, BPA at a mean ± SD concentration of 2046 ± 75 ng/g. However, the BPA concentrations found in the separator gel of the two batches of the vacuum tubes were varied by sevenfold. The problem with contaminated vacuum tubes was fixed with the further use of glass tubes without a separator gel. The second BPA contamination case reports on significant leaching of BPA out of rubber HPLC vial septa. Within eight consecutive injections using the same septum, the BPA concentration in the vial progressively increased from a value of zero at the first injection to 7.8 ng/ml at the eighth injection, while the septa itself contained BPA at average ± SD of 3386 ± 699 ng/g. The problem with contaminated HPLC vial septa was fixed with the further use of more chemically inert septa materials, e.g. silicone/PTFE.

KEYWORDS:

• Bisphenol A
• background contamination
• blood sampling tubes
• separator gel
• vial septa
• HPLC

Acknowledgements

The author would like to express gratitude to Mateja Kastelic, B. Sc. Chem. Eng., Simon Pavlič, Gorazd Skubic, DVM, and colleagues at the University of Ljubljana, Veterinary Faculty for their assistance and advice.

Disclosure statement

The author declares to have no competing interests.

Additional information

Funding

This work was financed by the Javna agencija za raziskovalno dejavnost Republike Slovenije –Slovenian Research Agency (ARRS) within the framework of the P4-0092 Research Program.