Analysis of pharmaceutical adulterants in plant food supplements by UHPLC-MS/MS

Screening the quality of legal and illegal dietary supplements by LC-MS/MS

Dietary supplements are widely consumed. However, the lack of mandatory testing results in limited data on their quality, particularly in Eastern Europe. In this study, 21 legally registered and 9 illegal supplements, seized from an underground facility by the Polish Police, were examined. Contaminants were screened by utilising high-performance liquid chromatography coupled with untargeted mass spectrometry. The analysis identified 32 contaminants in the 30 dietary supplements examined. Untargeted analysis revealed a concerning issue: the intentional adulteration of both legal and illegal supplements with pharmacologically active substances that are prohibited in this category of products. This study indicated that many dietary supplements are of low quality due to deliberate adulteration or inadequate manufacturing conditions. The presence of unregistered or unapproved substances in these supplements poses serious health risks. Strong legal regulations are essential to address this issue effectively.

Disclosing Frauds in Herbal Food Supplements Labeling: A Simple LC-MS/MS Approach to Detect Alkaloids and Biogenic Amines

Food supplements are a category of products perceived safe and therefore commonly used by different categories of consumers without any particular attention or precaution. However, health risks associated with the consumption of supplements containing undeclared substances cannot be excluded. A variety of analytical methods are used to control supplement quality composition, but usually, these procedures are complex and time-consuming. Here, we report the results of a simple and fast liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, to detect and quantify simultaneously different categories of active molecules, such as biogenic ammines and natural alkaloids that at high doses can produce negative health effect in consumers. Three categories of products intended for body weight loss, energy boosting, and erectile dysfunction treatment, purchased through e-commerce sites and from local supermarkets, were analyzed (n = 91). The caffeine, synephrine, agmatine sulfate, yohimbine, phenethylamine, and icariin were correctly separated and identified with good precision (RSD < 20%) and recovery (89-109%). The identification and quantification of the analytes in real samples highlighted that the 26% of the samples were not compliant with labeling, confirming that frauds are very common also in the natural supplements market. This LC-MS/MS method could be easily used to test natural supplements in order to check the correct labeling and to protect consumers from potential health risks and food frauds.

QSPR Modeling of Fungicides Using Topological Descriptors

A topological index is a real number that is obtained from a chemical graph's structure. Determining the physiochemical and biological characteristics of a variety of medications is useful since it more accurately represents the theoretical characteristics of organic molecules. This is accomplished using degree-based topological indices. The QSPR research has improved the structural understanding of the physiochemical properties of fungicides. Thirteen fungicides are examined for some of their physiochemical properties, and a QSPR model is built using nine of the drugs' topological indices. Here, we examine the degree to which the topological indices and physiochemical attributes are connected. To do this, we create networks connecting each of the topological indices to the properties of fungicides and computationally construct topological indices of the drugs mentioned above. According to this QSPR model, the melting point, boiling point, flash point, complexity, surface tension, etc. of fungicides are strongly connected. It was discovered that the topological indices (TIs) applied to the fungicides more accurately represent their theoretical features and show a strong correlation with their physical attributes.

LC-HRMS analysis of 13 classes of pharmaceutical substances in food supplements

Food supplements should not contain substances considered unsafe or pose a health risk to consumers. In recent years illegal adulterants have been found in various functional foods without notification of their presence or amount in the labelling. In this study, a validated method was developed and applied as a screening method to detect 124 forbidden substances belonging to 13 classes of compounds in food supplements. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) and a simple and rapid extraction protocol was applied to 110 food supplements collected from the internet market or during official controls in Italy. The percentage of non-compliant samples was 4.5%, relatively high compared with the official control results for these substances usually obtained on other food matrices. The results suggested the need to strengthen controls in this field to detect food supplement adulteration, which represents a potential health risk for the consumer.

Quality of Calcium Food Supplements: Evaluation Compared to Manufacturers' Declarations

Calcium (Ca) is a macronutrient necessary for the proper functioning of an organism. In the case of insufficient consumption with diet, its deficiencies can be supplemented with food supplements (FS). These supplements are used, for example, as an auxiliary in the prevention of osteoporosis, allergies, hair loss or nail brittleness. The purpose of the study was to assess the compliance of Ca content with the manufacturers' declaration. The material consisted of 108 FS. Ca content was determined by atomic absorption spectrometry (AAS). It was shown that 1.9% of the samples were characterized by a Ca content that was too low in comparison to the manufacturer's declaration, while a content that was relatively too high was found in 54.6% of FS. The quality of FS should be monitored to ensure patient safety.

Discrimination of Adulterated Ginkgo Biloba Products Based on 2T2D Correlation Spectroscopy in UV-Vis Range

Ginkgo biloba is a popular medicinal plant widely used in numerous herbal products, including food supplements. Due to its popularity and growing economic value, G. biloba leaf extract has become the target of economically motivated adulterations. There are many reports about the poor quality of ginkgo products and their adulteration, mainly by adding flavonols, flavonol glycosides, or extracts from other plants. In this work, we developed an approach using two-trace two-dimensional correlation spectroscopy (2T2D COS) in UV-Vis range combined with multilinear principal component analysis (MPCA) to detect potential adulteration of twenty G. biloba food supplements. UV-Vis spectral data are obtained for 80% methanol and aqueous extracts in the range of 245–410 nm. Three series of two-dimensional correlation spectra were interpreted by visual inspection and using MPCA. The proposed relatively quick and straightforward approach successfully differentiated supplements adulterated with rutin or those lacking ginkgo leaf extract. Supporting information about adulteration was obtained from the difference between the DPPH radical scavenging capacity of both extracts and from chromatographic (HPLC-DAD) fingerprints of methanolic samples.

A Rapid Screening Method for Sibutramine Hydrochloride in Natural Herbal Medicines and Dietary Supplements

Herbal weight loss drugs are becoming more widely used in the fight against obesity, but ineffective regulation of these products have resulted in harmful additives. These products may contain adulterants such as sibutramine hydrochloride that may result in serious adverse health events including death. This work established a color precipitation reaction-based rapid screening method for illegal adulteration of sibutramine hydrochloride in natural herbal medicines (NHM) and dietary supplements (DS). While a variety of chromatography- and electrophoresis-based systems have been reported to measure this analyte, they generally suffer from high costs, complicated sample preparation, and a costly analytical infrastructure. In contrast, we present a simple, handheld kit to assay for sibutramine. The performance metrics of this tool include an average detection time of approximately 3 minutes, which is markedly shorter than conventional methods (HPLC or HPLC-MS, etc.), a detection limit of 0.1 mg per aliquot, and an accuracy of 99.02% (n = 820). More strikingly, the sensitivity is 100% (n = 278), and the specificity is 98.52% (n = 542). The rapid test kit developed from this screening method was evaluated by FDA. In summary, this screening method is a rapid, simple, and low-cost tool for the detection of sibutramine in NHM and DS with superior selectivity and sensitivity. For these reasons, this method is especially suitable for underdeveloped settings because it can be employed onsite without any instrumentation. In addition, this approach could rapidly exclude most of the negative samples to boost efficiency in large-scale samples assay. If necessary, positive samples can undergo further alternate testing methods to confirm the positive results of sibutramine hydrochloride content.

HPLC-UV-QDa analysis of Citrus aurantium-labelled pre-workout supplements suggest only a minority contain the plant extract

Bitter orange (Citrus aurantium) is a common ingredient in pre-workout supplements with purported weight-loss and performance-enhancing effects. Supplements listing Citrus aurantium or p-synephrine have been associated with reports of adverse cardiovascular events attributed to the active biogenic amines, p-synephrine, p-octopamine or p-tyramine. Additionally, questions have been raised as to the authenticity of the plant-derived active components listed on the supplement labels. The aim of this study was to determine the quantities of these amines in a sample of pre-workout supplements which specifically listed Citrus aurantium, and assess the authenticity of plant material by comparing the ratios of amines found to that found in Citrus aurantium standardized reference materials (SRM). The quantities of amines in the supplements and SRMs were determined using a validated high-performance liquid chromatography-single quadrupole mass spectrometry (HPLC-UV-QDa) method. In the Citrus aurantium SRMs the quantities of trace amines found ranged from 5.30 to 38.00 mg/g (synephrine) 0.14-0.35 mg/g (octopamine) and 0.15-1.90 mg/g (tyramine) with an average ratio of 100:1:5 (synephrine: octopamine: tyramine). Only 42 % (5/12) of the supplements tested had ratios consistent with that found in the SRMs. The average trace amine ratio in those supplements was 100:1:3 while the quantities of trace amines found ranged from 0.35 to 31.31 mg/g (synephrine); 0.005 - 0.10 mg/g (octopamine) and 0.01-1.51 mg/g (tyramine). For the remaining supplements, some did not contain any detectable levels of trace amines or only synephrine was detected with concentrations ranging from 0.003 - 0.95 mg/g. These results suggest a role for authenticity/quality assurance testing of pre-workout supplements and more stringent regulation of pre-workout supplements.

Multi-Class Determination of 64 Illicit Compounds in Dietary Supplements Using Liquid Chromatography-Tandem Mass Spectrometry

In this work, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for screening and confirmation of 64 illicit compounds in dietary supplements. The target compounds were illegally used pharmaceutical drugs, prohibited compounds, and not authorized ingredients for different therapeutics (sexual enhancement, weight loss, muscular strengthening, and relaxing products). The validation procedure was performed to evaluate selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was >0.98 in the range of 0.5-200 µg L-1. The LOQs were in the range 1-10 µg kg-1 for all target compounds. The accuracy (expressed as recovery) was 78.5-114%. The precision (expressed as the relative standard deviation) was below 9.15%. The developed method was applied for the determination of illicit compounds in dietary supplements collected from websites. As a result, the total detection rate was 13.5% (27 samples detected in 200 samples). The concentrations of detected samples ranged from 0.51 to 226 mg g-1. The proposed methodology is suitable for monitoring the adulteration of illicit compounds in dietary supplements.

Identification of adulteration in botanical samples with untargeted metabolomics

Adulteration remains an issue in the dietary supplement industry, including botanical supplements. While it is common to employ a targeted analysis to detect known adulterants, this is difficult when little is known about the sample set. With this study, untargeted metabolomics using liquid chromatography coupled to ultraviolet-visible spectroscopy (LC-UV) or high-resolution mass spectrometry (LC-MS) was employed to detect adulteration in botanical dietary supplements. A training set was prepared by combining Hydrastis canadensis L. with a known adulterant, Coptis chinensis Franch., in ratios ranging from 5 to 95% adulteration. The metabolomics datasets were analyzed using both unsupervised (principal component analysis and composite score) and supervised (SIMCA) techniques. Palmatine, a known H. canadensis metabolite, was quantified as a targeted analysis comparison. While the targeted analysis was the most sensitive method tested in detecting adulteration, statistical analyses of the untargeted metabolomics datasets detected adulteration of the goldenseal samples, with SIMCA providing the greatest discriminating potential. Graphical abstract.

Screen for Potential Candidate Alternatives of Sargentodoxa cuneata from Its Six Adulterants Based on Their Phenolic Compositions and Antioxidant Activities

Daxueteng, the liana stem of Sargentodoxa cuneata, is a widely used Traditional Chinese Medicine facing the overflow of its commercial adulterants. A method for discriminating adulterants and screening potential candidate alternatives of S. cuneata was thus established. Total phenols and flavonoids of S. cuneata and its six adulterants and their abilities to scavenge DPPH^• and ABTS•+, to absorb peroxyl radicals (ORAC), and to inhibit AAPH-induced supercoiled plasmid DNA strand scission were comprehensively assessed. Polygonum cuspidatum and Bauhinia championii, two of the six adulterants of S. cuneate, shared considerably higher antioxidant activities as well as phenolic contents and, therefore, were considered as potential candidate alternatives. Phenolic compositions of the two potential candidate alternatives and S. cuneata itself were further determined by UPLC-QTOF-MS/MS. Totally 38 phenolics, including four hydroxybenzoic acids, two tyrosols, two caffeoylquinic acids, seven flavanol or its oligomers, two lignans, three hydroxycinnamic acids, six stilbenes, seven anthraquinones, and five flavanones were determined from three species. Furthermore, contents of different phenolic categories were semi-quantified and the major antioxidant contributors of S. cuneata and the two potential candidate alternatives were subsequently determined. It is concluded that tyrosols and caffeoylquinic acids were unique categories making great antioxidant contributions in S. cuneata and thus were considered as effective biomarkers in distinguishing its potential candidate alternatives.

A new approach to ion exchange chromatography with conductivity detection for adulterants investigation in dietary supplements

The extent of adulteration of dietary supplements has significantly increased in recent years. This situation worries health authorities and requires auxiliary analytical tools for the investigation of illegal substances purposely added. Ion exchange chromatography with conductivity detection is a consolidated analytical technique for the determination of inorganic compounds in various matrices. This technique has been applied to the pharmaceutical characterization of mainly impurities and degradation products. This work presents a new approach to ion exchange chromatography as a screening method to investigate the presence of amfepramone, femproporex, sibutramine, bisacodyl and amiloride in dietary supplements advertised for weight loss. The method was optimized and validated using a Metrosep C4 100/4.0 cation exchange column. The mobile phase consisted of 1.8 mm HNO₃ containing 2% acetonitrile (v/v), with a flow rate of 0.9 ml min^-1 , and nonsuppressed conductivity detection was applied. The limits of detection and quantification varied from 1.01 to 3.62 mg L^-1 and from 1.48 to 8.72 mg L^-1 , respectively. The proposed method was successful applied to 78 solid dietary supplement samples, in two of which adulterations were found. Moreover, ion exchange chromatography with conductivity detection could be easily used for quality control without prior complex sample pre-treatment.

Detection of adulterants in dietary supplements with Ginkgo biloba extract by attenuated total reflectance Fourier transform infrared spectroscopy and multivariate methods PLS-DA and PCA

The infrared spectroscopy with attenuated total reflectance (ATR) sampling coupled with chemometric methods has been applied to non-destructive detection of adulterants in dietary supplements containing Ginkgo biloba extract. The sample set comprised the spectra of six drugs and sixteen dietary supplements with ginkgo leaf extract. Spectral data (900-1800 cm^-1) were analyzed using multivariate partial least squares regression combined with a discriminant analysis (PLS-DA). The second derivative of spectra followed by mean centering was used as pre-processing method. Three models were constructed and validated for detection of potential adulterants: kaempferol, quercetin, and rutin. The iPLS-DA classification models achieved about 87.5%, 93,7%, and 87,5% of correct classification for adulteration with kaempferol, quercetin and rutin, respectively. The results obtained from classification models were verified by chromatographic fingerprints of unhydrolyzed sample extracts. Two-trace two-dimensional asynchronous correlation maps were constructed from pairs of spectra (each dietary supplement spectrum vs. averaged spectrum of drugs) and then analyzed by multiway PCA which revealed good discrimination between samples.

Assessment of 83 pharmaceuticals in WWTP influent and effluent samples by UHPLC-MS/MS: Hourly variation

The removal efficiency of pharmaceuticals in wastewater treatment plants (WWTPs) is variable and some of these compounds pass these plants almost intact and others presenting a removal efficiency close to 100%. Their incomplete removal results in a continuous discharge of pharmaceuticals into the environment. To assess the profile of contamination of influents and effluents over a day, a set of 83 pharmaceuticals were evaluated hourly in a WWTP in Leiria, Portugal. The composite samples of the influent and effluent were also collected. Concentrations varied from <MDL for ketoprofen, clarithromycin, ofloxacin, and diltiazem to 63.97 μg/L for caffeine in the WWTP influent composite sample and <MDL for clarithromycin, bupropion, and diltiazem to 2.01 μg/L for O-desmethylvenlafaxine for effluent composite sample. Concentrations in the range of μg/L were found for hydroxyibuprofen, salicylic acid, d,l-norephedrine, and caffeine in the WWTP influent, and diclofenac, carbamazepine, O-desmethylvenlafaxine in the WWTP effluents. For the samples collected hourly, thirty-eight and twenty-nine pharmaceuticals were detected in at least one WWTP sample. In the WWTP influent the total concentration of detected pharmaceuticals was higher between 15 and 22 h and lower in the period from 23 to 10 h in the morning. In the WWTP effluent, a slight variation was noticed throughout the sampling hours. Carbamazepine, fluoxetine, sertraline, atorvastatin, caffeine, simvastatin, and trazodone were the pharmaceuticals with risk quotient (RQ) >1 in WWTP influents, and carbamazepine, fluoxetine, sertraline the pharmaceuticals with an RQ > 1 in WWTP effluents.

Rapid screening of sulfonamides in dietary supplements based on extracted common ion chromatogram and neutral loss scan by LC-Q/TOF-mass spectrometry

There is an increasing amount of dietary supplements that are adulterated with diuretics and anti-diabetic drugs; this has become a global problem due to the wide distribution of dietary supplements and the serious negative health effects of the adulterants. In this study, a rapid screening method was developed for detection and confirmation of 35 sulfonamides in supplements by ultra-high performance liquid chromatography quadrupole/ time of flight mass spectrometry. For effective extraction of sulfonamides from dietary supplements, four extraction protocols including HLB and WAX solid-phase extraction, Quick Easy Cheap Effective Rugged and Safe method, and pH-controlled liquid–liquid extraction were evaluated, and pH-controlled liquid–liquid extraction method was shown to be the most effective with high recovery efficiency and low matrix effect. Rapid separation of 35 sulfonamides was achieved with the UHPLC C18 column (150 × 2.1 mm, 1.7 um) within 7 min using ammonium acetate aqueous solution (pH 8) and acetonitrile as the mobile phase. From the MS/MS spectra of sulfonamides, common ions (m/z 77.9650 [SO₂N]⁻ and m/z 79.9812 [SO₂NH₂]⁻) and neutral molecule loss fragments (HCl and SO₂) were observed according to their structural characteristics. Extracted common ion chromatograms and neutral loss scan of these characteristic fragments could effectively apply for rapid screening of sulfonamides in various types of supplements. A reduced mass tolerance window of ±5 ppm was useful for detecting targeted and untargeted sulfonamides and could avoid false positive and false negative results. Overall calibration curves within dynamic range for all targets were shown to be linear with a correlation coefficient R² > 0.995 and limits of detection ranged from 0.04 to 11.18 ng/g for all sulfonamides. The established method was successfully applied for screening and confirmation of sulfonamides in various supplements. The developed method will be helpful for the identification of sulfonamide diuretics and anti-diabetics in dietary supplements, promoting public health and consumer safety.

Detection and identification of multiple adulterants in plant food supplements using attenuated total reflectance-Infrared spectroscopy

Due to the rising popularity of dietary supplements, especially plant food supplements, and alternative herbal medicines, a whole market developed and these products became freely available through internet. Though several searches revealed that at least a part of these products, especially the ones obtained from websites disclosing their physical identity, are aldulterated with pharmaceutical compounds. This causes a threat for public health, since these compounds are not declared and therefore adverse effects will not immediately be related to the product. The more the adulterants can interfere with other medicinal treatments. Since the present active pharmaceutical ingredients are not declared on the package and the products are sold as 100% natural or herbal in nature, it is very difficult for custom personnel to discriminate between products to be confiscated or not. Therefore easy to apply analytical approaches to discriminate between adulterated and non-adulterated products are necessary. This paper presents an approach based on infrared spectroscopy combined with attenuated total reflectance (ATR) and partial least squares- discriminant analysis (PLS-DA) to easily differentiate between adulterated and non- adulterated plant food supplements and to get a first idea of the nature of the adulterant present. The performance of PLS-DA models based on Mid-IR and NIR data were compared as well as models based on the combined data. Further three preprocessing strategies were compared. The best performance was obtained for a PLS-DA model using Mid-IR data with the second derivative as preprocessing method. This model showed a correct classification rate of 98.3% for an external test set. Also eight real samples were screened using the model and for seven of these samples a correct classification was obtained. Generally it could be concluded that the obtained model and the presented approach could be used at customs to discriminate between adulterated and non-adulterated herbal food supplements and even get a first idea of the nature of the adulterant present. The more the presented approach hardly needs sample preparation.