Abstract
The illegal adulteration of sildenafil in herbal food supplements and alcoholic drinks immensely threatens human health due to its harmful side-effects. Therefore, it is important to accurately detect and identify the presence of sildenafil in alcoholic drinks. In this study, Opto Trace Raman 202 (OTR 202) was used as surface enhanced Raman spectroscopy (SERS) active colloids to detect sildenafil. The results demonstrated that the Raman enhancement factor (EF) of OTR 202 colloids reached 1.84 × 107 and the limits of detection (LODs) of sildenafil in health wine and liquor were found to be as low as 0.1 mg/L. Moreover, the SERS peaks of 645, 814, 1235, 1401, 1530 and 1584 cm−1 could be qualitatively determined as sildenafil characteristic peaks and the relationship between Raman peak intensity and sildenafil concentration in health wine and liquor were different. There was a good linear correlation between Raman peak intensity, and sildenafil concentration in health wine ranged 0.1–1 mg/L (0.9687< R2 < 0.9891) and 1–10 mg/L (0.9701 < R2 < 0.9840), and in liquor ranged 0.1–1 mg/L (0.9662 < R2 < 0.9944) and 1–20 mg/L (0.9625 < R2 < 0.9922). The relative standard deviations (RSD) were less than 5.90% (sildenafil in health wine) and 9.16% (sildenafil in liquor). The recovery ranged 88.92–104.42% (sildenafil in health wine) and 90.09–104.55% (sildenafil in liquor). In general, the sildenafil in health wine and liquor could be rapidly and quantitatively determined using SERS technique, which offered a simple and accurate alternative for the determination of sildenafil in alcoholic drinks.
Highlights
Sildenafil is one of the inhibitors of phosphodiesterase type 5 (PDE-5), which is frequently added into health supplementary products for the treatment of erectile dysfunction (ED) in males [1]
We report a rapid and quantitative determination method of sildenafil in health wine and liquor based on SERS with Opto Trace Raman 202 (OTR 202) colloids
We found that the Raman enhancement factor (EF) of OTR 202 colloids could reach 1.84 × 107 and the proposed method showed good performance for sildenafil in health wine and liquor detection and the LODs were found to be as low as 0.1 mg/L; both were far lower than 1%
Summary
Sildenafil is one of the inhibitors of phosphodiesterase type 5 (PDE-5), which is frequently added into health supplementary products for the treatment of erectile dysfunction (ED) in males [1]. Ramirez et al [18] quantified plasma levels of sildenafil and its metabolite by liquid chromatography (LC) with a C18 reverse-phase column and UV detection; the limits of detection (LODs) and quantification were 1 and 10 ng/mL, respectively. Oris et al [19] determined ardenafil, sildenafil, tadalafil, testosterone, procaine, lidocaine, prilocaine, and benzocaine in cosmetic creams by using HPLC method with ultraviolet diode array (UV-DAD) and electrospray ionization mass spectrometry (ESI-MS). The results show a good determination coefficient (R2 ≥ 0.99) and the limits of quantification range 2.5–7.8 μg/g and 3.3–8.9 ng/g for HPLC-UV-DAD assay and HPLC-ESI-MS assay, respectively. Kee et al [20] differentiated two groups of PDE-5 inhibitors including four sildenafil- and three thiosildenafil-like analogs by Orbitrap-mass spectrometry, indicating that the identification of PDE-5 analogs in dietary supplements can be possibly done in a wide concentration range. The results show that the limits of quantification of sildenafil are 20 and 5 ng/mL using HPLC-UV and HPLC-MS methods, respectively
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
