Development of a UHPLC-FLD method for the analysis of ergot alkaloids and application to different types of cereals from Luxembourg

Risks for animal health related to the presence of ergot alkaloids in feed

The European Commission requested EFSA to provide an update of the 2012 Scientific Opinion of the Panel on Contaminants in the Food Chain (CONTAM) on the risks for animal health related to the presence of ergot alkaloids (EAs) in feed. EAs are produced by several fungi of the Claviceps and Epichloë genera. This Opinion focussed on the 14 EAs produced by C. purpurea (ergocristine, ergotamine, ergocornine, α- and β-ergocryptine, ergometrine, ergosine and their corresponding 'inine' epimers). Effects observed with EAs from C. africana (mainly dihydroergosine) and Epichloë (ergovaline/-inine) were also evaluated. There is limited information on toxicokinetics in food and non-food producing animals. However, transfer from feed to food of animal origin is negligible. The major effects of EAs are related to vasoconstriction and are exaggerated during extreme temperatures. In addition, EAs cause a decrease in prolactin, resulting in a reduced milk production. Based on the sum of the EAs, the Panel considered the following as Reference Points (RPs) in complete feed for adverse animal health effects: for pigs and piglets 0.6 mg/kg, for chickens for fattening and hens 2.1 and 3.7 mg/kg, respectively, for ducks 0.2 mg/kg, bovines 0.1 mg/kg and sheep 0.3 mg/kg. A total of 19,023 analytical results on EAs (only from C. purpurea) in feed materials and compound feeds were available for the exposure assessment (1580 samples). Dietary exposure was assessed using two feeding scenarios (model diets and compound feeds). Risk characterisation was done for the animals for which an RP could be identified. The CONTAM Panel considers that, based on exposure from model diets, the presence of EAs in feed raises a health concern in piglets, pigs for fattening, sows and bovines, while for chickens for fattening, laying hens, ducks, ovines and caprines, the health concern related to EAs in feed is low.

Development, in-house validation and application of a method using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the quantification of 12 ergot alkaloids in compound feeds

Introduction

Ergot alkaloids (EAs) are toxic substances naturally produced by Claviceps fungi. These fungi infest a wide range of cereals and grasses. When domestic animals are exposed to EAs through contaminated feeds, it is detrimental to them and leads to significant economic losses. For that reason, it is important to monitor feed for the presence of EAs, especially with methods enabling their determination in processed materials.

Material and Methods

Ergot alkaloids were extracted with acetonitrile, and dispersive solid phase extraction (d-SPE) was used for clean-up of the extracts. After evaporation, the extracts were reconstituted in ammonium carbonate and acetonitrile and subjected to instrumental analysis using high-performance liquid chromatography with fluorescence detection. The developed method was validated in terms of linearity, selectivity, repeatability, reproducibility, robustness, matrix effect, limits of quantification and detection and uncertainty. The EA content of 40 compound feeds was determined.

Results

All the assessed validation parameters fulfilled the requirements of Regulation (EU) 2021/808. At least one of the monitored alkaloids was determined in 40% of the samples. The EAs with the highest incidence rate were ergocryptine, ergometrinine and ergocornine. The total concentrations of EAs ranged from under the limit of quantification to 62.3 μg kg-1.

Conclusion

The results demonstrated that the developed method was suitable for simultaneously determining twelve EAs in compound feed and could be used for routine analysis.

Occurrence of Ergot Alkaloids in Major and Minor Cereals from Northern Italy: A Three Harvesting Years Scenario

Ergot alkaloids (EAs), mycotoxins produced mainly by fungi of the Claviceps genus, have been frequently reported in rye, while their increasingly frequent occurrence in other cereals is likely related to weather conditions, with the incidence of ergot sclerotia in winter grains being related to heavy rainfall and moist soils at critical periods. However, compared to other regulated mycotoxins, data about the prevalence and occurrence of EAs in major and minor cereals harvested in the Mediterranean growing areas are still scant. In this regard, the current study reported the occurrence of EAs in 18 genotypes of winter cereals harvested over 3 years from an experimental field located in North Italy which were analyzed by HPLC-MS/MS. Results indicate a widespread occurrence of all the major EAs in all the considered cereal crops, especially under supportive meteorological conditions. EA contamination was dependent on the harvest year (p < 0.0001) which was particularly high in 2020 for all the considered species. The results also demonstrated a large co-occurrence of EAs with 98 cereal samples out of 162 contaminated with at least one of the 12 EAs (60% positive samples) in the range LOD: 15,389 μg/kg (median value: 2.32 μg/kg), expressed as the sum of the EAs. Rye was confirmed to be the crop more susceptible to the fungal infection (EAs content up to 4,302 μg/kg). To the best of our knowledge, we have reported the accumulation of EAs in tritordeum (LOD: 15,389 μg/kg) and in emmer (LOD: 1.9 μg/kg) for the first time.

The Impact of Storage Temperature and Time on Ergot Alkaloid Concentrations

Ergot sclerotia produce toxic secondary metabolites, ergot alkaloids, that infect cereal crops and grasses. Ergot alkaloids have two isomeric configurations: the C-8-R-isomer (R-epimer), and the C-8-S-isomer (S-epimer). Ergot contaminated matrices, such as cereal grains or grasses, may be stored for extended periods at various temperatures before being analyzed, utilized, or consumed. This study assessed the concentration of six common ergot alkaloids in both configurations found in naturally contaminated wheat over time (one, two, and four months) at different temperatures (room temperature, +4 °C, and -20 °C) using ultra-high-performance liquid chromatography-tandem mass spectrometry. The data indicate that the total ergot concentration within a natural contaminated sample varies over time at room temperature, +4 °C, and -20 °C. The total ergot concentration increased until month two, and decreased at month four, independent of temperature (p < 0.05). The total R-epimer concentration appeared to be less stable over time than the total S-epimer concentration. The changes in the total R and total S-epimer concentrations may have been caused by changes in the ergocristine and ergocristinine concentrations, respectively. Time and temperature should be considered when storing potentially contaminated matrices in a laboratory or practical agriculture situations. Quantification of ergot contaminated matrices should occur prior to their use to ensure the most reliable estimates of the concentration of ergot.

In-House Validation of an Efficient and Rapid Procedure for the Simultaneous Determination and Monitoring of 23 Mycotoxins in Grains in Korea

A high-performance liquid chromatography tandem mass spectrometry method is described for the simultaneous determination of mycotoxins, including Ergot alkaloids (EAs), in 3 types of grains. The extraction of 23 mycotoxins was evaluated and performed by using a modified QuEChERS-based sample preparation procedure. The proposed method was fully validated on spiked grain samples (barley, wheat and oat) to assess the linearity, limit of detection (LOD) and limit of quantitation (LOQ), matrix effects, precision and recovery. After validation, this method was applied to 143 samples of various types of 3 grains from the Republic of Korea to survey the level of mycotoxin contamination in Republic of Korean grains. A total of 42 grain samples (29%) were contaminated with at least one of these mycotoxins at levels higher than the LOQ. The results demonstrated that the procedure was suitable for simultaneously determining these mycotoxins in cereals and could be performed for their routine analysis in mycotoxin laboratories.

Undertaking a New Regulatory Challenge: Monitoring of Ergot Alkaloids in Italian Food Commodities

The present manuscript reports on monitoring data of 12 ergot alkaloids (EAs) in cereal and cereal-derived products, collected in Italy over the period 2017-2020, for official control purposes under the edge of the Commission Recommendation 2012/154/EU on the monitoring of the presence of EAs in feed and food. To these purposes, an LC-MS/MS method was set up and applied, after in-house verification of its analytical performance. Besides satisfactory recoveries and precision, the method's quantification limits proved suitable to assess the compliance of cereals and cereal-based foods with the recently issued EU maximum permitted levels (Commission Regulation 2021/1399/EU). The validity of the generated data was also evaluated through the adoption of four proficiency tests, from which acceptable z-score values (-2 ≤ z ≤ 2) were obtained. The method was then applied to analyse a total of 67 samples, collected in Italy over the period 2017-2020. The samples consisted of 18 cereal grains, 16 flours (14 of wheat and 2 of spelt) and 31 other types of cereals derivatives (including 9 for infants). Overall, the EAs analysis returned a high percentage of left-censored data (>86%). Among the positive samples, the highest contamination levels, up to 94.2 µg/kg, were found for ergocristine (12% incidence), followed by ergocristinine (7% incidence) with levels of up to 48.3 µg/kg.

Determination of principal ergot alkaloids in swine feeding

BACKGROUND

Ergot alkaloids are secondary metabolites produced by fungi in the genus Claviceps. They contaminate a large variety of cereals, such as rye, triticale, wheat and barley. The ingestion of contaminated cereals might cause adverse health effects in humans and animals. In fact, pigs, cattle, sheep, and poultry are involved in sporadic outbreaks and, although there are several studies about occurrence of ergot alkaloids in grain cereals, there are scarce studies focused on compound feed.

RESULTS

Twelve ergot alkaloids have been quantified in 228 feed samples intended for swine. The analytes were extracted using QuEChERS with Z-Sep+ as sorbent in the clean-up step, which reduced the matrix effect, allowing limits of quantification between 2.1 and 21.7 μg kg^-1 . The analytes were subsequently quantified by ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). A total of 29 samples (12.7%) revealed contamination by at least one ergot alkaloid, and among contaminated samples, 65% were contaminated by more than one. Only 6 of 12 target ergot alkaloids showed concentrations above the limit of quantification. The concentrations for individual ergot alkaloids ranged between 5.9 μg kg^-1 for ergosinine to 145.3 μg kg^-1 for ergometrine (the predominant ergot alkaloid), while the total ergot alkaloid content ranged from 5.9 to 158.7 μg kg^-1 .

CONCLUSIONS

The occurrence of ergot alkaloids in feed samples in Spain seems to be lower than in other regions of Europe. All the samples fulfilled current recommendations of the feed industry about practical limits for ergot alkaloids in pig feeds. This suggests that the feeds are safe for pig consumption, regarding the presence of ergot alkaloids. © 2021 Society of Chemical Industry.

Occurrence of Ergot Alkaloids in Barley and Wheat from Algeria

The natural occurrence of six major ergot alkaloids, ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers, were investigated in 60 cereal samples (barley and wheat) from Algeria. Ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and a QuEChERS extraction method were used for sample analysis. The results revealed that 12 out of 60 samples (20%) were contaminated with ergot alkaloids. Wheat was the most contaminated matrix, with an incidence of 26.7% (8 out of 30 samples). The concentration of total ergot alkaloids ranged from 17.8 to 53.9 µg/kg for barley and from 3.66 to 76.0 μg/kg for wheat samples. Ergosine, ergokryptine and ergocristine showed the highest incidences in wheat, while ergometrine was the most common ergot in barley.

Covariation of Ergot Severity and Alkaloid Content Measured by HPLC and One ELISA Method in Inoculated Winter Rye across Three Isolates and Three European Countries

Ergot caused by Claviceps purpurea is a problem for food and feed security in rye due to the occurrence of toxic ergot alkaloids (EAs). For grain elevators and breeders, a quick, easy-to-handle, and cheap screening assay would have a high economic impact. The study was performed to reveal (1) the covariation of ergot severity (= percentage of sclerotia in harvested grain) and the content of 12 EAs determined by high performance liquid chromatography (HPLC) and (2) the covariation between these traits and results of one commercial enzyme linked immunosorbent assays (ELISA). In total, 372 winter rye samples consisting of a diverse set of genotypes, locations from Germany, Austria, and Poland over two years, and three isolates were analyzed. Ergocornine and α-ergocryptine were detected as major EAs. Ergocristinine occurred as a minor component. Claviceps isolates from different countries showed a similar EA spectrum, but different quantities of individual EAs. A moderate, positive covariation between ergot severity and EA content determined by HPLC was observed across two years (r = 0.53, p < 0.01), but large deviation from the regression was detected. ELISA values did neither correlate with the HPLC results nor with ergot severity. In conclusion, a reliable prediction of the EA content based on ergot severity is, at present, not possible.

Epimerization of ergot alkaloids in feed

Chronic intake of cereals contaminated with ergot alkaloids can cause ergotism and result in the loss of toes and fingers or even death. Today, due to common risk management practices, ergotism is rare as a human disease but remains a problem in livestock husbandry. Each alkaloid coexists under two forms (R and S), though only the R-form presents toxic effects. The epimerization occurs spontaneously but the mechanisms remain globally unknown. Therefore, different processing methods were evaluated for their respective influences on the epimerization. The results suggest that ergotamine and ergosine are very stable ergot alkaloids, and neither their concentrations, nor their respective R/S ratios, are significantly influenced by heating, protic solvents or UV light. In contrast, for ergocristine, ergokryptine, ergocornine and ergometrine, heating can decrease the concentrations of these alkaloids and heat, protic solvents and UV light influence the R/S ratio towards the S-form, though the respective influence on the epimerization of these compounds is variable. In addition, the total concentration of all ergot alkaloids is reduced through heating. However, all these effects are not strong enough to change the composition of ergot alkaloids in feed substantially and to transform toxic feed into non-toxic feed.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Developments in mycotoxin analysis: an update for 2018-19

This review summarises developments on the analysis of various matrices for mycotoxins that have been published in the period from mid-2018 to mid-2019. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes, and zearalenone are covered in individual sections. Advances in sampling strategies are also discussed in a dedicated section. In addition, developments in multi-mycotoxin methods – including comprehensive mass spectrometric-based methods as well as simple immunoassays – are also reviewed. This critical review aims to briefly present the most important recent developments and trends in mycotoxin determination as well as to address limitations of the presented methodologies.

Optimized Analysis of Ergot Alkaloids in Rye Products by Liquid Chromatography-Fluorescence Detection Applying Lysergic Acid Diethylamide as an Internal Standard

Analysis of ergot alkaloids remains a topic of importance and the European Food Safety Authority (EFSA) has encouraged laboratories to provide monitoring data for the further evaluation of their occurrence in food and feed. While LC-MS/MS has dominated developments in recent years, LC-FLD is still more widespread, especially in developing countries. To improve the analysis of ergot alkaloids by LC-FLD, we developed an improved protocol introducing lysergic acid diethylamide (LSD) for internal standardization. Several aspects such as the composition and pH of the extraction medium, type of sorbent and conditions applied for solid-phase extraction/clean-up, use of a keeper during final evaporation and the type of syringe filter used for filtration prior to injection were thoroughly investigated. Optimized conditions comprise extraction by ethyl acetate, methanol and 28% aqueous ammonia in combination with basic aluminum oxide for extract clean-up. Use of a keeper was found inappropriate as LC-FLD analysis was significantly affected by co-eluting keeper components. Similar observations were made with some of the investigated syringe filters, where polytetrafluoroethylene (PTFE) proved to be the most suitable. Validation and application of the optimized methodology to real samples provided limits of detection and quantification suitable for the evaluation of relevant ergot alkaloid contaminations in rye and bakery products with superior precision that was facilitated by the introduced internal standard, LSD.

Developments in mycotoxin analysis: an update for 2017-2018

This review summarises developments that have been published in the period from mid-2017 to mid-2018 on the analysis of various matrices for mycotoxins. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes, and zearalenone are covered in individual sections. Advances in sampling strategies are discussed in a dedicated section, as are methods used to analyse botanicals and spices, and newly developed comprehensive liquid chromatographic-mass spectrometric based multi-mycotoxin methods. This critical review aims to briefly discuss the most important recent developments and trends in mycotoxin determination as well as to address limitations of the presented methodologies.