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BACKGROUND: Chlorate is an effective herbicide, but also a byproduct of chlorinating agents used to disinfect water, which is one of the reasons why it is regularly found in food. Perchlorate is a ubiquitous contaminant, which is naturally occurring in the environment but also released from anthropogenic sources such as the industrial use of certain natural fertilizers. Chlorate affects the hematological system, and perchlorate the thyroid. OBJECTIVE: Implement and validate a simple and robust analytical method for the accurate determination of chlorate and perchlorate in baby food, infant and adult formulas, and ingredients thereof, which is suited for its application in routine environments where a broad variety of food commodities must be analyzed simultaneously. METHOD: Typically, analytes are extracted with a mixture of water, acidified methanol, and dichloromethane. Optionally, for dairy products and byproducts, extraction can be performed with water, acidified methanol, and EDTA, followed by two steps of cleanup (freezing out and dispersive solid-phase extraction with C18 in acetonitrile). Quantitative determination is carried out by isotopic dilution liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: The method was single-laboratory validated in five Nestlé Quality Assurance Centers (NQACs) in a comprehensive range of representative matrixes of different categories such as baby foods, infant/adult formulas, and ingredients, with results generally in agreement with the acceptance criteria of the Standard Method Performance Requirement (SMPR®) 2021.001 defined by AOAC INTERNATIONAL, in terms of representative matrixes validated, LOQs, trueness, and precision.The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments. CONCLUSION: The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments. HIGHLIGHTS: The AOAC Expert Review Panel approved the present method as AOAC Official First Action 2022.06.

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A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) based multi-residue method has been developed and validated for the extraction and determination of pesticides in fatty matrices by gas chromatography tandem mass spectrometry. Extraction and clean-up were performed according to QuEChERS principles widely used for non-fatty matrices, with main difference, a higher solvent/sample- ratio followed by a 6-fold preconcentration step, ensuring good extractability and sensitivity. A validation according to SANTE guidelines was performed using a olive and sunflower oils mixture 1:1, w/w as representative matrix, at 2 concentration levels (5 and 50 µg/kg) targeting 176 GC-amenable pesticides. Most compounds fulfilled the validation criteria, with a limit of quantification of 5 µg/kg for 137 compounds , and of 50 µg/kg for 24 compounds. Afterwards, the method performance was tested in six different fatty matrices with 73-90% of the analytes fulfilling the performance criteria at 5 µg/kg depending on the matrix.

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Next to furan, other alkylfurans such as 2- and 3-methylfuran, 2-ethylfuran, 2,5-dimethylfuran, and 2-pentylfuran have been found concurrently in thermal processed food and fruit juices. To ensure an accurate quantification of these compounds, a method based on isotope dilution using all six respective internal standards and gas chromatography coupled to mass spectrometry was developed. Two injection techniques, static head space (HS) and solid phase micro extraction (SPME), were tested and compared for their performance. Validation was based on a single laboratory validation under repeatability condition. Good data for both techniques in baby food and cereals were obtained. Furthermore, validation was conducted successfully on fruit juices and infant formula using SPME injection and on coffee using HS injection. LOQ for all matrices was established at 5 µg/kg and 200 µg/kg in coffee samples, which corresponds to the lowest fortification level. Recovery was between 80 % and 110 % and repeatability obtained below 16 % at 50 µg/kg (7.4 % at 10 mg/kg for coffee samples), except few slight outliers.

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Two methods based on a modified QuEChERS sample preparation and either LC coupled to atmospheric pressure ionisation and high-resolution MS or GC coupled to electron ionisation and tripled quadrupole MS have been assessed for the quantification of folpet and phthalimide in tea and other dry herbal infusions. Both methods have been fully validated in green tea and further checked in black tea, verbena and rooibos, and they performed according to the SANTE/11813/2017 criteria at the target LOQ concentration level (50 µg/kg). These methods allow the accurate quantification of folpet in the selected matrices according to the new EU residue definition, which includes phthalimide. Phthalimide is the main metabolite and degradation product of folpet, although according to recent studies, it could be generated from different sources than folpet breakdown, such as food processing or analysis by GC.

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Accurate quantification of folpet is problematic because it degrades into phthalimide during sample preparation and analysis by gas chromatography (GC). Thus, EU regulation was recently modified to include phthalimide in the folpet residue definition. However, recent studies have shown that phthalimide could also be generated from different sources, which could lead to an overestimation of the phthalimide content and therefore to false positives. GC coupled with either negative chemical ionisation and single quadrupole mass spectrometry, or electron ionisation with triple quadrupole mass spectrometry (GC-EI-MS/MS), were evaluated for the determination of folpet and phthalimide in food. Both methods were validated in 4 different matrices namely apple puree, rice flour, raspberry puree and infant formula. Better selectivity and precision were obtained with GC-EI-MS/MS. Negligible amounts of phthalimide was found in blank matrices, and validation results met the SANTE/11813/2017 criteria in all matrices at the LOQ concentration levels by using GC-EI-MS/MS.

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A fast and simple analytical method was developed and characterized for the determination of aflatoxins (B1, B2, G1 and G2) in rice. The procedure is based on a simple solid-liquid extraction without further clean-up, and analysis by ultra-high performance liquid chromatography coupled with fluorescence detection. Fluorescence emission of aflatoxins B1 and G1 was enhanced by post-column chemical derivatization using pyridinium bromide perbromide. The analytical method was satisfactorily characterized in white and brown rice. Under optimum conditions, external calibration in solvent could be used for quantification purposes and limits of quantification were below the maximum contents established by the European Union regulation for these contaminants/commodity group combination (0.07-0.14 µg/kg for white rice and 0.20-0.28 µg/kg for brown rice). Recovery studies carried out at three different concentration levels (0.5, 2 and 5 µg/kg) showed values in the range of 84.5-105.3%, and RSDs ≤ 5%.

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Two low-pressure columns (Bio-Beads SX-3) and three high-pressure GPC columns were compared for clean-up of a wide range of pesticides in fatty matrices of vegetable or animal origin. The GPC fractions were analyzed by GC-MS/MS and LC-MS/MS without additional clean-up. The performance of the GPC clean-up on the five column types was compared in terms of solvent consumption, lipid removal, pesticide recovery and repeatability. It was found that for fatty matrices, mainly consisting of high molecular weight triglycerides i.e. most vegetable oils and animal fats, good fractionation is obtained for the majority of the pesticides. On the other hand, for fats and oils containing relatively high amounts of low molecular weight triglycerides, i.e. butter fat and palm kernel oil, none of the columns provided sufficient clean-up and cause interferences and system contamination, especially in the case of GC-MS/MS analysis. For the latter case, best results in terms of lipid removal and pesticide recovery were obtained on a set (2×300mmlength) of narrow bore (7.5mm ID) columns packed with 5µm PL Gel material. Column loadability is, however, much lower on that set of columns compared the other evaluated GPC columns, impairing overall method sensitivity.

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A simple, effective and reliable method for the determination of eight sulfonamide antibiotics (sulfadiazine, sulfapiridine, sulfamerazine, sulfamethazine, sulfachloropiridazine, sulfamethoxazole, sulfadoxine, sulfadimethoxin) in chicken muscle and eggs by liquid chromatography and fluorescence detection has been developed and validated. Sulfonamides do not present native fluorescence, however their direct determination was achieved by on-line post-column photochemical derivatization by UV irradiation. Sample treatment was based on QuEChERS with several modifications depending on the matrix. Egg extracts were cleaned-up using PSA for the dispersive solid phase extraction step. On the other hand, a new clean-up sorbent, Supel™ QuE Z-Sep(+), has been successfully applied in chicken muscle extract and has proved to be effective for interference removal from this matrix. Under optimum conditions, recoveries from 65.9 to 88.1%, relative standard deviations lower than 10% (except for sulfachloropiridazine), and limits of quantification (LOQs) from 14 to 85 µg kg(-1) were achieved. Thus, the method complies with current European requirements.

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A feasibility study for producing a matrix reference material for selected polycyclic aromatic hydrocarbons (PAHs) in baby food is reported. A commercially available baby food, containing carrots, potatoes, tomato, white beans and meat, was spiked with the so-called 15 + 1 PAHs included in the PAHs priority list for food of the EU, at a mass fraction level of 1 µg/kg. The contaminated baby food was further processed by autoclaving, freezing or freeze drying. The homogeneity of the three materials (bottle-to-bottle variation) and their short-term (4 weeks) and long-term (18 months) stability at different temperatures were assessed. To this end, an analytical method based on a solid-liquid extraction followed by cleaning up with gel permeation chromatography (GPC) and solid phase extraction (SPE) and GC-IDMS determination, was validated in-house. It could be demonstrated that the procedure fulfilled the demands for application to the homogeneity and isochronous stability studies for the candidate reference materials targeted here. All three materials proved to be sufficiently homogeneous for the intended use. Measurements on the autoclaved material provided the most promising results in terms of envisaged shelf life, although freeze drying was also found to be a suitable processing technique for most of the investigated PAHs. These results are an important step towards the development of a matrix reference material for PAHs in a processed food matrix in a presentation very similar to routine samples.

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In this paper we proposed a reverse high performance liquid chromatography method for the simultaneous determination of three N-methylcarbamates (NMCs) named carbofuran, carbaryl and methiocarb, using the post-column chemiluminescence (CL) detection with the luminol reaction. This method is based on the enhancing effect of these analytes on the CL emission generated by the oxidation of luminol with potassium permanganate in alkaline medium. The separation was reached in less than 14 min using a C18 column and an isocratic binary mobile phase consisting of acetonitrile:water (50:50, v/v) pumped at a flow rate of 1 mL min(-1). CL reagents (luminol and KMnO(4)) were incorporated by means of a peristaltic pump and were firstly mixed using a three-way connector. Then this stream was mixed with the eluate using another three-way connector just before reaching the detection cell. The optimization of variables affecting the CL reaction (reaction medium, concentration, flow rate of reagents and distance between both connectors) were optimized by means of experimental designs. Ethiofencarb, a NMC which has nowadays fallen into disuse was used as internal standard. For the analysis of theses pesticides in real water samples a pre-treatment step consisting of solid phase extraction (SPE) was conducted in order to reach sensitivity levels below the legal maximum concentration permitted. In the case of vegetable sample, SPE was used for matrix cleaning purpose.

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Tranexamic acid (TA) is a synthetic antifibrinolytic agent that is being considered as a candidate adjuvant drug for site-specific pharmaco-laser therapy of port wine stains. For drug utility studies, a high-performance liquid chromatography (HPLC)-fluorescence method was developed for the quantification of TA in blood. Platelet-poor plasma was prepared, size-separated using 3kDa cut-off centrifuge filters, and derivatized with naphthalene-2-3-dicarboxaldehyde (NDA) and cyanide. The excess of NDA was quenched after 2 min by adding tryptophan. The derivatives were separated on a 2.1mm C18 column using an acetate buffer/acetonitrile gradient. Excellent separation from plasma background was obtained at pH 5.5. Quantification was carried out at 440/520 nm. The limit of detection was 0.5 microM and the mean+/-SD recovery from whole blood was 81.7+/-10.9%. Derivatized TA samples were stable for at least 36 h at 4 degrees C. The method was successfully applied to a heat-induced TA release study from thermosensitive liposomes.

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A simple, fast chemiluminescence (CL) flow-injection (FI) method based on the reaction of luminol with KMnO(4) in alkaline medium has been described for the direct determination of carbofuran. The method is based on the enhancing effect in the emission light from the oxidation of luminol produced in presence of carbofuran. The optimisation of instrumental and chemical variables influencing the CL response of the method has been carried out by applying experimental design, using the proposed flow-injection manifold. Under the optimal conditions, the CL intensity was linear for a carbofuran concentration over the range of 0.06-0.5mugml(-1), with a detection limit of 0.02mugml(-1). The method has been successfully applied to the determination of carbofuran residues in spiked water and lettuce samples.

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This study presents the first analytical application of the luminol chemiluminescence (CL) reaction for the sensitive detection of carbamate residues. Some experiments have been carried out to check the influence of the presence of traces of a N-methylcarbamate (carbaryl) on the CL emission produced from the oxidation of luminol using different oxidants, showing a significant enhancing effect on the CL emission when the oxidation of luminol is produced by potassium permanganate in alkaline medium, this enhancement being proportional to the carbaryl concentration. This fact has permitted the establishment of a sensitive chemiluminescence flow-injection (CL-FIA) method for the direct determination of carbaryl. The optimization of instrumental and chemical variables influencing the CL response has been carried out by applying experimental designs. Under the optimal conditions, the CL intensity was linear for a carbaryl concentration over the range 5-100 ng/mL with a detection limit of 4.9 ng/mL. This luminol-KMnO4-based FIA-CL system in basic medium shows an easy, fast and cheap alternative detection mode for the analysis of carbaryl residues in environmental water samples.

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