Page 116 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

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followed by separation on a CN-column and qTOF detection. Product ions
in the range of m/z 100 to 500 from four parent ions, corresponding to
sildenafil and its three metabolites, were monitored.

2.5 LC/MS Analysis of Natural Compounds
of Forensic Relevance

Digitalis glycosides: digoxin, digitoxin, deslanoside, digoxigenin, and digi-
170
toxigenin were determined with ESI/LC/MS/MS. The drugs were extracted
from whole blood or urine by SPE using Oasis HLB cartridges at alkaline
pH. Chromatographic separation was performed on ODS column in
ACN–ammonium formate gradient. An abundant ammonia adduct (M +
+
NH ) and much less abundant protonated quasi-molecular ion (M + H) +
4
were observed in ESI. In APCI, the substances dissipated to many fragments.
Time-scheduled selected reaction monitoring was applied, using (M +
+
NH ) ions as precursor ions and one fragment for each compound as a
4
product ion. The recovery ranged from 11 to 64%; the LODs were from
0.05 to 1 mg/l. The method was applied for therapeutic drug monitoring of
cardiac glycosides.
171
Lacassie et al. reported a case of a 36-year-old female who ingested a
concoction of foxglove leaves (Digitalis purpurea) and was admitted to an
emergency unit some hours later. She developed sinus bradycardia, abdominal
pain, nausea, and vomiting. After five days of treatment she was discharged
without symptoms. The cardiac glycosides acetyldigitoxin, convallatoxin, desl-
anoside, digitoxigenin, digitoxin, digoxin, gitaloxin, gitoxin, latanoside C,
methyldigoxin, oleandrin, proscilardin, and strophantidin in blood and urine
samples of the patient were determined with LC/ESI/MS. The drugs were
extracted with an organic solvent mixture after acetonitrile precipitation and
separated on an ODS column in a gradient of ACN–ammonium formate pH
3.0. For each analyte the protonated quasi-molecular ion (M + H) and one
+
or two fragment ions were monitored. The recovery was 67.8 to 98.6%, and
the limit of detection 1 to 10 mg/l. This sensitivity was adequate for acute
poisoning cases but not for therapeutic drug monitoring. Glycoside levels in
blood were monitored from 8 to 100 h after intoxication. In a case reported
by Gaillard and Pepin, veratridine and cevadine (toxins present in Veratrum
album) were identified and quantitated in the blood of two persons found in
a mountain lake. In their stomachs, seeds of Veratrum were identified.
LC/ESI/MS was used. Measured blood concentrations were 0.17 and 0.40 mg/l
for veratridine and 0.32 and 0.48 mg/l for cevadine. 172
Oleander (Nerium oleander L.) is an evergreen, widely distributed shrub,
which contains cardenolides — toxic cardiac glycosides such as oleandrin,

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