Jw. Jaroszewski et al., DETERMINATION OF DIETHYLCARBAMAZINE, AN ANTIFILARIAL DRUG, IN HUMAN URINE BY H-1-NMR SPECTROSCOPY, Journal of pharmaceutical and biomedical analysis, 14(5), 1996, pp. 543-549
H-1-NMR spectroscopy is a convenient method for determination of dieth
ylcarbamazine (DEC) in urine, and can be used to monitor medication wi
th the drug. Urine samples were mixed with 10%, of deuterium oxide as
a spectrometer field frequency lock, which is the only sample pretreat
ment required. Tailored excitation with the 1 (3) over bar 3 (1) over
bar pulse was used for water peak suppression. The quantification of D
EC was carried out with the triplet of the N-ethyl group, for which th
e T-1 relaxation rime was 1 s. In aqueous solutions, amounts below 1 m
u g ml(-1) of DEC could be easily detected. In urine, the detectabilit
y depended on the level of chemical noise but was better than 10 mu g
ml(-1). The accuracy and precision of the method were better than 15%.
Analysis of urine from volunteers receiving a single therapeutic dose
of DEC (6 mg kg(-1) body weight orally) showed that the drug was elim
inated in unchanged form during 2 days, in agreement with earlier resu
lts. The concentration of DEC in urine several hours after the intake
exceeded 100 mu g ml(-1) making the H-1-NMR assay rapid and easy. No s
ignificant amounts of the N-oxide of DEC could be detected.