SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

A43
SIMULTANEOUS DETERMINATION OF SILDENAFIL. VARDENAFIL AND TADALAFIL AS
ADULTERANTS IN DIETARY SUPPLEMENTS BY LC-ESI-MS
K. Saisho*, H. Kamakura, M. Kawamura, R. Kikura-Hanajiri, Y. Goda
National Institute of Health Sciences, I-IS-I, Kamiyoga, Setagaya-ku, Tokyo 15S-S50I, Japan
In recent years, there is a problem with illegally added prescription ingredients and/or their synthetic
analogues (as active adulterants) in dietary supplements. Prolonged or excessive consumption of these
products may cause possible serious health risks to some users. It has been reported that sildenafil (SDF),
which is therapeutically used for penile erectile dysfunction, is one of the active adulterants in products
advertising roborant nutrition. Moreover, its structurally similar anti-impotence drugs, vardenafil (VDF) and
tadalafil (TDF), may be alternative adulterants of SDF. In this study, a simultaneous analytical procedure for
three anti-impotence drugs, SDF, VDF and TDF (as adulterants in dietary supplements advertising roborant
nutrition) was developed using LC-ESI-MS.
These drugs were extracted with the solvent consisted of acetonitrile and distilled water containing I %
formic acid (4: 1, v/v) under ultrasonication. The separation was achieved on an Inertsil ODS-3 column (2.1 x
150 mm, 5 Om) at 40°C. The following gradient system was used with mobile phase A(5 mM ammonium
formate buffer (pH 3.5) I acetonitrile (75:25, v/v» and mobile phase B (acetonitrile); B: 0 % (0-3 min), B
linear from 0 to 30 % (3-13 min), B: 30 % (13-30 min). The flow rate was at 0.3 mLlmin. LC-MS with ESI
interface in the positive ion mode was used. The linear regression ofthe peak area ratios versus concentration
in standard solution was fitted over the concentration range of 10 - 10000 ng/mL (SDF), 5 5000 ng/mL
(VDF) and 50 - 25000 ng/mL (mF). All calibration curves were obtained with correlation coefficients of
greater than 0.9990. The recoveries of SDF, VDF and mF spiked a functional food at O.Olmg/mg
concentrations were 9S.8%, 100.2% and 99.S %, respectively.
The developed method was applied to the determination of SDF, VDF and TDF in 91 dietary supplements
obtained from the Japanese market. SDF was identified in seven samples and their contents were in the range
of24.2 mg 120.9 mg /capsule or bottle. In addition to SDF, homosildenafil (a synthetic analogue ofSDF)
was also detected in one of the seven samples. TDF was detected in one sample and the content was 0.32
mg/capsule, while VDF was not found in any sample. Moreover, a new synthetic analogue of SDF,
hydroxyhomosildenafil, which has never been reported, was also identified in the sample.
Keywords: Anti-impotence drugs, LC-MS, Dietary supplements
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