Abstract:
In some developing countries, p-phenylenediamine (PPD) is used in combination with Henna as hair
dye or skin decoration. A sensitive LC–MS/MS method was developed and validated for the simultaneous
determination of p-phenylenediamine (PPD) and its metabolites N-acetyl-p-phenylenediamine (MAPPD)
andN,N-diacetyl-p-phenylenediamine (DAPPD) inhumanblood. Acetanilide was used as an internal standard
(IS). The LC–MS/MS was operated under multiple reaction-monitoring mode using the electrospray
positive ionization technique. The transition ions m/z 109→92, m/z 151→92, m/z 193→92, and m/z
136→77 were selected for the quantification of PPD, MAPPD, DAPPD, and IS, respectively. The linear
range was 10–2000 ng/mL for all the compounds. The absolute recoveries were 51.94, 56.20 and 54.88%
for PPD, MAPPD and DAPPD, respectively. Intra- and inter-assay imprecision were lower than 14% (RSD),
and the bias of the assay was lower than 15% for all the compounds. The stability studies demonstrated
that critical degradation for PPD in blood samples and autosampler occurred after 6 h, while MAPPD and
DAPPD were stable in blood samples and the autosampler up to 48 h and 24 h, respectively. This newly
developed method allows for the detection of PPD and its metabolites in blood samples in the clinical
and forensic setting.
