Cases of poisoning by p-phenylenediamine (PPD) are detected sporadically. Recently
an article on the development and validation of a LC-MS/MS method for the
detection of PPD and its metabolites, N-acetyl-p-phenylenediamine (MAPPD) and
N,N-diacetyl-p-phenylenediamine (DAPPD) in blood was published. In the current
study this method for detection of these compounds was validated and applied to
urine samples. The analytes were extracted from urine samples with methylene
chloride and ammonium hydroxide as alkaline medium. Detection was performed by
LC-MS/MS using electrospray positive ionization under multiple reaction-monitoring
mode. Calibration curves were linear in the range 5–2000 ng/mL for all analytes.
Intra- and inter-assay imprecisions were within 1.58–9.52% and 5.43–9.45%
respectively, for PPD, MAPPD and DAPPD. Inter-assay accuracies were within -7.43
and 7.36 for all compounds. Lower limit of quantification was 5 ng/mL for all
analytes. The method, which complies with the validation criteria, was successfully
applied to the analysis of PPD, MAPPD and DAPPD in human urine samples
collected from clinical and postmortem cases.