Sulfonic Acid-Functionalized SBA-15 as Strong Cation-Exchange Sorbent for Solid-Phase Extraction of Atropine and Scopolamine in Gluten-Free Grains and Flours

Application of Rice Husk-Derived SBA-15 Bifunctionalized with C18 and Sulfonic Groups for Solid-Phase Extraction of Tropane, Pyrrolizidine, and Opium Alkaloids in Gluten-Free Bread

Rice husk (RH), a globally abundant agri-food waste, presents a promising renewable silicon source for producing SBA-15 mesoporous silica-based materials. This study aimed to synthesize and bifunctionalize SBA-15 using RH as a silica precursor, incorporating sulfonic and octadecyl groups to create a mixed-mode sorbent, RH-SBA-15-SO3H-C18, with reversed-phase and cation exchange properties. The material's structure and properties were characterized using advanced techniques, including X-ray diffraction, infrared spectroscopy, N2 adsorption-desorption isotherms, nuclear magnetic resonance, and electron microscopy. These analyses confirmed an ordered mesoporous structure with a high specific surface area of 238 m2/g, pore volume of 0.45 cm3/g, pore diameter of 32 Å, and uniform pore distribution, highlighting its exceptional textural qualities. This sorbent was effectively utilized in solid-phase extraction to purify 29 alkaloids from three families-tropane, pyrrolizidine, and opium-followed by an analysis using ultra-high performance liquid chromatography coupled to ion-trap tandem mass spectrometry. The developed analytical method was validated and applied to gluten-free bread samples, revealing tropane and opium alkaloids, some at concentrations exceeding regulatory limits. These findings demonstrate that RH-derived RH-SBA-15-SO3H-C18 is a viable, efficient alternative to commercial sorbents for monitoring natural toxins in food, offering a sustainable solution for repurposing agri-food waste while addressing food safety challenges.

Improving the food safety of bakery products by simultaneously monitoring the occurrence of pyrrolizidine, tropane and opium alkaloids

The exponential number of food alerts about concerning levels of some plant-alkaloids, such as pyrrolizidine, tropane and opium alkaloids, have stressed the need to monitor their occurrence in foods to avoid toxic health effects derived from their intake. Therefore, analytical strategies to simultaneously monitor the occurrence of these alkaloids should be developed to ensure food safety an comply with regulations. Accordingly, this work proposes an efficient multicomponent analytical strategy for the simultaneous extraction of these alkaloids from commercial bakery products. The analytical method was validated and applied to the analysis of 15 samples, revealing that 100% of them contained at least one of the target alkaloids, in some cases exceeding the maximum limits legislated. Moreover, in two samples the 3 different alkaloid families were detected. These results confirm the importance of simultaneously monitoring these alkaloids in food and highlight also considering some opium alkaloids in current legislation.

Reports of tropane alkaloid poisonings and analytical techniques for their determination in food crops and products from 2013 to 2023

Food safety is crucial to attaining food security and sustainability. Unsafe foods for human and animal consumption lead to product recalls and rejection, negatively impacting the global economy and trade. Similarly, climate change can adversely affect the availability of safe and nutritious food at the table. The changing climatic conditions and global food trade and transport can make the movement of toxic plants possible, resulting in food crops being increasingly invaded by some species of plants that produce toxic secondary metabolites, such as tropane alkaloids (TAs). Datura stramonium from the Solanaceae plant family is an invasive and virulent plant that produces high amounts of two TAs, atropine and scopolamine. Various food poisoning events following accidental or deliberate ingestion of foods contaminated by atropine and scopolamine from seeds of D. stramonium have been recorded in different locations globally. Due to these incidents, regulatory agencies require the development of plant toxin detection methods that can be used in the food chain as early as possible. This systematic review thus focuses on the TA determination techniques in food and feeds published between 2013 and 2023. A particular focus was given to the sample preparation methods, the improvements of each technique claimed, and data to support the performance of each method, especially the ability to measure at or below the maximum level. The review concludes with other technological advancements, including rapid spectroscopy, electrophoresis, and colorimetric methods, as well as the possibility of coupling with smartphones for use in on-farm detection and the challenges in applying them.

Design and Optimisation of Sustainable Sample Treatments Based on Ultrasound-Assisted Extraction and Strong Cation-Exchange Purification with Functionalised SBA-15 for Opium Alkaloids in Ground Poppy Seeds

An analysis methodology was optimised and validated for the quantification of opium alkaloids (OAs) in ground poppy seeds. This involved ultrasound-assisted extraction (UAE) and solid-phase extraction (SPE) purification before analysis using a high-performance liquid chromatography mass spectrometry detector (HPLC-MS/MS). UAE was optimised through the design of experiments with three factors and a three-level full factorial design. For SPE optimisation, a commercial material was compared with a previously synthesised material of SBA-15 silica functionalised with sulfonic groups (SBA-15-SO3-). The synthesised material demonstrated superior efficiency with only 25 mg and proved to be reusable for up to four cycles. The methodology was properly validated in terms of linearity, limits of detection and quantification, and selectivity. Matrix effects were negligible; adequate recovery values (85-100%) and inter-day and intra-day precision (≤15%) were obtained. The greenness of the method was evaluated with the AGREEprep metric scale, being more environmentally friendly compared to OA analysis methods. Finally, the method was applied to different samples of ground poppy seeds and revealed a concentration of 140 mg/kg of morphine equivalents in one of the samples, surpassing the legislatively established limits by sevenfold. This highlights the need to analyse these types of samples to mitigate potential public health issues.

Emerging Issues on Tropane Alkaloid Contamination of Food in Europe

The occurrence of tropane alkaloids (TAs), toxic plant metabolites, in food in Europe was studied to identify those TAs in food most relevant for human health. Information was extracted from the literature and the 2016 study from the European Food Safety Authority. Calystegines were identified as being inherent TAs in foods common in Europe, such as Solanum tuberosum (potato), S. melongena (eggplant, aubergine), Capsicum annuum (bell pepper) and Brassica oleracea (broccoli, Brussels sprouts). In addition, some low-molecular-weight tropanes and Convolvulaceae-type TAs were found inherent to bell pepper. On the other hand, atropine, scopolamine, convolvine, pseudotropine and tropine were identified as emerging TAs resulting from the presence of associated weeds in food. The most relevant food products in this respect are unprocessed and processed cereal-based foods for infants, young children or adults, dry (herbal) teas and canned or frozen vegetables. Overall, the occurrence data on both inherent as well as on associated TAs in foods are still scarce, highlighting the need for monitoring data. It also indicates the urge for food safety authorities to work with farmers, plant breeders and food business operators to prevent the spreading of invasive weeds and to increase awareness.

Improved Analytical Approach for Determination of Tropane Alkaloids in Leafy Vegetables Based on µ-QuEChERS Combined with HPLC-MS/MS

This work presents an optimized methodology based on the miniaturization of the original QuEChERS (μ-QuEChERS) followed by liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) for the determination of tropane alkaloids (TAs), atropine, and scopolamine in leafy vegetable samples. The analytical methodology was successfully validated, demonstrating quantitation limits (MQL) ≤ 2.3 ng/g, good accuracy, and precision, with recoveries between 90–100% and RSD ≤ 13% for both analytes. The method was applied to the analysis of TA-producing plants (Brugmansia versicolor, Solandra maxima, and Convolvulus arvensis). High concentrations of scopolamine were found in flowers (1771 mg/kg) and leaves (297 mg/kg) of B. versicolor. The highest concentration of atropine was found in flowers of S. maxima (10.4 mg/kg). Commercial mixed leafy vegetables contaminated with B. versicolor and S. maxima were analysed to verify the efficacy of the method, showing recoveries between 82 and 110% for both analytes. Finally, the method was applied to the analysis of eighteen samples of leafy vegetables, finding atropine in three samples of mixed leafy vegetables, with concentrations of 2.7, 3.2, and 3.4 ng/g, and in nine samples with concentrations ≤MQL. In turn, scopolamine was only found in a sample of chopped Swiss chard with a concentration ≤MQL.

Atropine and Scopolamine in Maize Products from the Retail Stores in the Republic of Serbia

The cereal grains, which represent the cultivated grasses fruits, supply almost half of the total caloric requirements for humans and provide more nourishment compared with any other class of the food. Out of many cereals used for food, maize, rice, and wheat are the most important food resources for humans, representing 94% of the total cereals consumption. According to the data of the Republic Institute of Statistics for the year 2018, the harvested areas of corn amount to 906,753 hectares. The production of about 7 million tons was achieved with an average yield of 7.7 t/ha according to the Ministry of Agriculture of the Republic of Serbia. Serbia is still among the ten largest exporters of wheat and corn in the world for the period of 2014/15–2017/18. More precisely, it ranks seventh in the export of corn. Utilization of maize products for food animal nutrition (1000 t) is 491,48, and for industrial processing (1000 t) 278,862 expressed as the total consumption (1000 t) is 769,910. Therefore, a total of 103 samples of maize products were analyzed for the presence of toxins, i.e., tropane alkaloids (TAs). The samples were collected from the retail stores in the Republic of Serbia in 2021 and analyzed for the presence of atropine and scopolamine (33 corn grits, 39 polenta, and 31 semolina samples). Therefore, the Recommendation 2015/976/EU on the monitoring of TAs in food was adopted by the EU Commission to obtain more occurrence data on TAs in food. The monitoring extent, however, is restricted because reliable analytical methods and appropriate sensitivity are limited. There was a limit of 1 g/kg for each atropine and scopolamine in cereals containing millet, sorghum, buckwheat, or their derivatives. All the samples were analyzed by the LC-MS/MS. The LOQ was set at 1.0 μg/kg. Out of the total 103 tested samples, 32 samples (31.1%) were contaminated with atropine and scopolamine in concentrations above the LOQ. The highest concentrations of the studied TAs were observed in a semolina sample-atropine: 58.80 μg/kg, scopolamine: 10.20 μg/kg. The obtained results indicate that the TAs concentrations are above the LOQ which can be considered potential human and animal health hazards.

Evaluation of Thermal Degradation of Tropane and Opium Alkaloids in Gluten-Free Corn Breadsticks Samples Contaminated with Stramonium Seeds and Baked with Poppy Seeds under Different Conditions

In this work, the thermal degradation of tropane and opium alkaloids was studied in samples of breadsticks prepared with corn flour, contaminated with seeds of Datura stramonium, and containing seeds of Papaver somniferum L. A total of seven different samples were prepared and eight alkaloids were studied, three tropane (atropine, scopolamine, and anisodamine) and five opium (morphine, codeine, thebaine, papaverine, and noscapine) alkaloids. For this purpose, a fast, easy and efficient method based on solid-liquid extraction (SLE) prior to the analysis by high-performance liquid chromatography with a diode array detector (HPLC-DAD) was developed and validated. Thermal degradation studies showed a decrease in the TAs and OAs content under baking (180 °C for 20 min) that was between 7–65% for atropine, depending on the preparation conditions used, between 35–49% for scopolamine and anisodamine, up to 100% for morphine and codeine and between 14–58% for thebaine, papaverine, and noscapine. Results also evidenced that degradation of morphine and codeine was higher when the seeds were added as topping to the breadsticks.

Recent advances of ordered mesoporous silica materials for solid-phase extraction

This review mainly focuses on the development and application of ordered mesoporous silica materials for solid-phase extraction in recent years. It overviews not only bare mesoporous silica but also the functionalized mesoporous silica with organic groups, molecularly imprinted polymers, and magnetic materials. These mesoporous silica materials were used as the extraction adsorbents in cartridge solid-phase extraction, dispersive solid-phase extraction, magnetic solid-phase extraction, micro-solid-phase extraction and matrix solid phase dispersion. Coupled with atomic emission spectrometry, chromatography or other detection methods, these techniques efficiently extracted and sensitively determined various targets, such as metal ions, perfluorocarboxylic acids, pesticides, drugs, endocrine disruptors, phenols, flavanones, polycyclic aromatic hydrocarbons, parabens and so on. Based on unique advantages of mesoporous silica materials, the developed analytical method successfully analyzed different matrix samples, like environmental water samples, soil samples, food samples, biological samples and cosmetics. In addition, the prospects of these materials in solid-phase extraction are presented, which can offer an outlook for the further development and applications.

Mesostructured Silicas as Cation-Exchange Sorbents in Packed or Dispersive Solid Phase Extraction for the Determination of Tropane Alkaloids in Culinary Aromatics Herbs by HPLC-MS/MS

In this work, Hexagonal Mesoporous Silica (HMS) and Santa Barbara Amorphous-15 (SBA-15) mesostructured silicas were synthesized and functionalized with sulfonic acid groups. The materials (HMS-SO3− and SBA-15-SO3−) were evaluated as strong cation exchange sorbents for sample extract clean-up, by solid phase extraction (SPE) and dispersive solid phase extraction, to determine atropine (At) and scopolamine (Sc) in commercial culinary aromatic herbs. Under optimized conditions, 0.25 g of sample was subject to solid−liquid extraction with acidified water (pH 1.0), and good recovery percentages were achieved for At and Sc using 75 mg of HMS-SO3− in SPE as the clean-up stage, prior to their determination by HPLC-MS/MS. The proposed method was validated in a thyme sample showing recoveries in the range of 70−92%, good linearity (R2 > 0.999), adequate precision (RSD ≤ 14%) and low limits (MDL 0.8−2.2 µg/kg and MQL 2.6−7.2 µg/kg for both analytes). Sixteen aromatic herbs samples (dried thyme, basil and coriander leaves) were analysed and At was found in fourteen samples over an interval of <5−42 μg/kg, whereas Sc was found in three of the sixteen samples studied (between <5−34 μg/kg). The amount of At and Sc found in some analysed samples confirms the importance of setting maximum levels of At and Sc in culinary aromatic herbs.

Occurrence and Chemistry of Tropane Alkaloids in Foods, with a Focus on Sample Analysis Methods: A Review on Recent Trends and Technological Advances

Tropane alkaloids (TAs) are natural toxins produced by different plants, mainly from the Solanaceae family. The interest in TAs analysis is due to the serious cases of poisoning that are produced due to the presence of TA-producing plants in a variety of foods. For this reason, in recent years, different analytical methods have been reported for their control. However, the complexity of the matrices makes the sample preparation a critical step for this task. Therefore, this review has focused on (a) collecting the available data in relation to the occurrence of TAs in foods for human consumption and (b) providing the state of the art in food sample preparation (from 2015 to today). Regarding the different food categories, cereals and related products and teas and herbal teas have been the most analyzed. Solid-liquid extraction is still the technique most widely used for sample preparation, although other extraction and purification techniques such as solid-phase extraction or QuEChERS procedure, based on the use of sorbents for extract or clean-up step, are being applied since they allow cleaner extracts. On the other hand, new materials (molecularly imprinted polymers, mesostructured silica-based materials, metal-organic frameworks) are emerging as sorbents to develop effective extraction and purification methods that allow lower limits and matrix effects, being a future trend for the analysis of TAs.

Guanidinylated SBA-15/Fe3O4 mesoporous nanocomposite as an efficient catalyst for the synthesis of pyranopyrazole derivatives

In this study, a novel mesoporous nanocomposite was fabricated in several steps. In this regard, SBA-15 was prepared by the hydrothermal method, next it was magnetized by in-situ preparation of Fe3O4 MNPs. After that, the as-prepared SBA-15/Fe3O4 functionalized with 3-minopropyltriethoxysilane (APTES) via post-synthesis approach. Then, the guanidinylated SBA-15/Fe3O4 was obtained by nucleophilic addition of APTES@SBA-15/Fe3O4 to cyanimide. The prepared nanocomposite exhibited excellent catalytic activity in the synthesis of dihydropyrano[2,3-c]pyrazole derivatives which can be related to its physicochemical features such as strong basic sites (presented in guanidine group), Lewis acid site (presented in Fe3O4), high porous structure, and high surface area. The characterization of the prepared mesoporous nanocomposite was well accomplished by different techniques such as FT-IR, EDX, FESEM, TEM, VSM, TGA, XRD and BET. Furthermore, the magnetic catalyst was reused at least six consequent runs without considerable reduction in its catalytic activity.

Simultaneous Determination of Furanic Compounds and Acrylamide in Insect-Based Foods by HPLC-QqQ-MS/MS Employing a Functionalized Mesostructured Silica as Sorbent in Solid-Phase Extraction

Insect-based products are novel foods (NF) that merit careful study. For this reason, in this work a method has been developed for the simultaneous analysis of four food processing contaminants (FPC), acrylamide (AA), 5-hydroxymethylfurfural, (HMF), 5-methylfurfural (MF) and furfural (F), in insect-based products (bars, crackers and flours) by high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (HPLC-QqQ-MS/MS). The method consisted of a solid-liquid extraction (SLE) with acidified water, followed by solid-phase extraction (SPE), using 100 mg of a sorbent based on mesostructured silica with a large pore functionalized with amino groups (SBA-15-LP-NH2). The analytical method was properly optimized and validated in a representative bar sample of pineapple & coconut with cricket flour (Ins-B-Pine-Coco) showing good accuracy, with recoveries ranging from 70-101% for the four analytes and adequate precision (RSD < 9%). Good linearity (R2 ≥ 0.995) and low method quantification limits for AA (between 1.3-1.4 µg/g), F (between 7.9-8.8 µg/g), MF (between 3.1-6.5 µg/g) and HMF (between 1.5-3.3 µg/g) were also obtained in all samples studied. The proposed method was successfully applied in eleven insect-based foods. Results revealed that insect-based bars can be a good alternative to traditional cereal bars to reduce dietary exposure to HMF; but, in order to reduce the exposure to AA, alternative formulations must be evaluated in the design of innovative insect-based crackers.