Determination of 26 anti-diabetic compounds in dietary supplements using a validated UPLC method.

The purpose of this study was to validate a rapid, simple and accurate method using ultra-performance liquid chromatography (UPLC) for the simultaneous determination of 26 anti-diabetic compounds in illegally adulterated dietary supplements. The method was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, recovery and stability. All compounds were separated with a resolution of over 1.5. The limits of detection and quantitation were 0.10-1.70 and 0.30-5.10 µg g-1 in a solid sample, respectively; the corresponding values were 0.10-1.25 and 0.30-3.75 µg ml-1 in a liquid sample. The correlation coefficient was > 0.99, precisions were 0.11-3.30% (intra-day) and 0.05-6.15% (inter-day), and accuracies were 83-108% (intra-day) and 85-109% (inter-day). The recoveries were measured with six dosage forms, and the results were acceptable as 87-117% with relative standard deviations ≤ 6.44%. The relative standard deviations of stability were ≤ 3.40% and the standard solution was stable for 48 h. Ninety-six samples were obtained from on/off-line markets and were analysed using the developed method. Among these samples, pioglitazone and glibenclamide were found in seven samples and the concentrations of each compound were 0.15% and 0.26-0.51%, respectively. With the increasing adulteration of dietary supplements with anti-diabetic drugs, this method may be helpful to protect public health and safety.

Simultaneous analysis of 35 specific antihypertensive adulterants in dietary supplements using LC/MS/MS.

A sensitive and specific LC/MS/MS method was developed for the simultaneous analysis of 35 compounds used for treating hypertension as adulterants in dietary supplements. The method was validated for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation, stability and recovery. The limit of detection and limit of quantitation ranged from 0.20 to 20.0 and 0.50 to 60.0 ng/g, respectively. The linearity was good (r2 > 0.999), with intra- and interday precision levels of 0.43-7.87% and 0.65-9.95% and the intra- and interday accuracies of 84.36-115.82% and 83.78-118.69%, respectively. The stability (relative standard deviation) was <14.75%. The mean recovery was 80.81-117.86% (relative standard deviation <10.00%). Ninety-seven commercial dietary supplements available in South Korea were analyzed. While none contained detectable amounts of the 35 antihypertensive compounds, the developed LC/MS/MS procedure can be used for routine analysis to monitor illegal adulteration in various forms of dietary supplements.

A rapid method for the simultaneous determination of 25 anti-hypertensive compounds in dietary supplements using ultra-high-pressure liquid chromatography.

A novel, stable, simple and specific ultra-performance liquid chromatography method with ultraviolet detection (205 nm) for the simultaneous analysis of 25 anti-hypertensive substances was developed. The method was validated according to the International Conference of Harmonisation guidelines with respect to linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ) and stability. From the ultra-performance liquid chromatography results, we identified the LOD and LOQ of solid samples to be 0.20-1.00 and 0.60-3.00 µg ml-1, respectively, while those of liquid samples were 0.30-1.20 and 0.90-3.60 µg ml-1, respectively. The linearity exceeded 0.9999, and the intra- and inter-day precisions were 0.15-6.48% and 0.28-8.67%, respectively. The intra- and inter-day accuracies were 82.25-111.42% and 80.70-115.64%, respectively, and the stability was lower than 12.9% (relative standard deviation). This method was applied to the monitoring of 97 commercially available dietary supplements obtained in Korea, such as pills, soft capsules, hard capsules, liquids, powders and tablets. The proposed method is accurate, precise and of high quality, and can be used for the routine, reproducible analysis and control of 25 anti-hypertensive substances in various dietary supplements. The work presented herein may help to prevent incidents related to food adulteration and restrict the illegal food market.

Simultaneous Analysis of Cannabinoid and Synthetic Cannabinoids in Dietary Supplements Using UPLC with UV and UPLC-MS-MS.

The primary purpose of this study was to develop and validate a method based on UPLC with UV and UPLC-MS-MS for the simultaneous analysis of different cannabinoids and synthetic cannabinoids in food as well as in herbal and dietary supplements. The limits of detection and quantitation of the method ranged from 0.1 to 0.3 and 0.3 to 0.9 µg/mL by UPLC with UV, respectively. The coefficient of determination was >0.999; the intra- and interday precision of the method were 0.1-3.7 and 0.9-4.1%, respectively. The intra- and interday accuracy were 94.8-103.1 and 98.3-100.9%, respectively. The mean recoveries of nine cannabinoids obtained from tablet samples ranged from 81.1 to 105.4%. The mean extraction recoveries of nine target cannabinoids obtained from various types of samples (tablets, capsules, powders, liquids, cookies and candies) ranged from 82.26 to 112.40%. The relative standard deviation (RSD) of the stability of the prepared sample solutions was <1.80%. Identification and quantification of the nine cannabinoids were accomplished by ion spray UPLC-MS-MS using multiple reaction monitoring. The UPLC-MS-MS method was validated for linearity (R(2) > 0.99); the precision was 0.1-4.0% (intraday) and 0.1-2.8% (interday), and the accuracy was 98.0-103.5% (intraday) and 97.1-103.2% (interday). The mean extraction recoveries of six types of samples were 82.2-114.5% and the RSD of stability was <6.54%, complying with the established international guidelines. The results indicated that the method can be used for rapid and accurate screening of cannabinoids present in food.

Development and validation of an LC-MS/MS method for the simultaneous analysis of 28 specific narcotic adulterants used in dietary supplements.

The purpose of this study was to develop a method to analyse the concentration of multiple illegal narcotics present in dietary supplements. To this end, we established and optimised a procedure using LC-MS/MS simultaneously to analyse 28 narcotic compounds in various forms of dietary supplements, including powders, tablets, liquids and capsules. In addition, candy and cookies that have also had detected cases of adulteration were also analysed. The specificity, linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), stability and recovery for these methods were validated accordingly. The LOD and LOQ of the LC-MS/MS ranged from 0.01-50.0 to 0.03-100 ng g(-1), respectively. The linearity of these results was good (r(2) > 0.99), with intra- and inter-day precision values of 0.2-5.2% and 0.2-4.8%, respectively. Further, the intra- and inter-day accuracies of this method were 97.0-103.4% and 94.6-103.1%, respectively. The stability RSD was less than 7.8%. The mean recovery for this LC-MS/MS procedure was 81.1-117.4%, with an RSD less than 9.8%. Following the validation of our method, we analysed 47 commercially available dietary supplements obtained in Korea. Whilst none of these samples had detectable amounts of the 28 specified narcotic adulterants, our novel LC-MS/MS procedure can be utilised comprehensively and continually to monitor illegal drug adulteration in various forms of dietary supplements.