Analytical Investigations of Toxic p-Phenylenediamine (PPD) Levels in Clinical Urine Samples with Special Focus on MALDI-MS/MS
Figure 3
Wet chemistry assay for spiked blank and clinical urine samples.
(A) Left row bottom to top: urine blank and 5 different spiked concentrations (25, 50, 100, 250 and 500 µmol/L). Right row top three vials: three clinical samples, which show a positive test result for PPD. (B) Concentration dependent transmittance (%) from 25–250 µmol/L on a spectrophotometer at 450 nm.