Commercially available non-opioid analgesics such as acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) have been used to adulterate some foods and dietary supplements. Considering the rapid growth of the dietary supplement market, it is essential to analyse various analgesics used for adulteration over a time period. Acetaminophen and 16 NSAIDs used to adulterate food and dietary supplements were simultaneously determined by LC-MS/MS. The method was validated by determining the coefficient of determinations, limit of quantification and recovery, and samples were analysed for the determination of analgesics. Consequently, acetaminophen, diclofenac, ibuprofen, indomethacin, naproxen and piroxicam were detected in 53 samples (n = 214). Ibuprofen was the most commonly used adulterant, which was detected in a wide concentration range (1.06-233.40 mg g(-1)) and was present in about one-third of the adulterated samples. Various types of samples, in particular pills and capsules (73.6% of the total positive samples), were found to be adulterated with non-opioid analgesics. Samples containing high concentrations of analgesics can have a deleterious effect on human health, and thus the continued monitoring of adulterated food and dietary supplements is essential to maintain a healthy life.
Keywords: LC-MS/MS; dietary supplements; non-opioid analgesics; non-steroidal anti-inflammatory drugs (NSAIDs).