Journal of AOAC International最新文献

Background: Quantitative NMR spectroscopy (qNMR) can be used to determine chemical purity. This applies to the resonating nuclei of all the present chemical species, enabling quantitation of the analyte against chemically non-identical calibrator molecules.

Objective: Validation approaches for determining chemical purity with qNMR are being endorsed by major pharmacopoeias and other standard-setting bodies. In this study, we investigated the purity determination, uncertainty evaluation, and method validation of imazosulfuron using qNMR to gain ISO 17034 accreditation.

Methods: We ensured the NIST traceability of imazosulfuron by calibrating 1,4-BTMSB-d  4 (determining its purity and uncertainty) using NIST PS 1 and then calibrating imazosulfuron using the calibrated 1,4-BTMSB-d  4. Purity and uncertainty determinations were performed using qNMR, as per the proposed revisions to the USP General Chapters <761> and <1761>. Method development and validation were performed as described in these chapters using the principles of Analytical Quality by Design (AQbD).

Results: First, we defined a target measurement uncertainty of ± 2.0% (k = 2) as the Analytical Target Profile (ATP). Next, we established robust operating parameters for qNMR and determined the purity and uncertainty of 1,4-BTMSB-d  4. Subsequently, we determined the purity and uncertainty of imazosulfuron using the calibrated 1,4-BTMSB-d  4 to verify that the qNMR method produced reportable values that met the ATP criteria.

Conclusions: The purity and uncertainty of imazosulfuron were 98.2% ± 1.2% (k = 2), meeting the ATP criteria. We then moved on to the next stage to monitor and ensure that the qNMR method remains properly controlled and satisfy the ATP criteria during routine use. Based on the above, we established a validation scheme that meets the requirements of ISO 17034 by leveraging AQbD considerations.

Highlights: The AQbD principles shift the focus of method validation toward procedure design and development, resulting in more rational design, efficient development, and validation.

Background: As the demand for natural colorants is expected to increase in the future, it is important to analyze pesticide residues to investigate the relationship between exposure and health risks. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) analytical method, which uses small-scale SPE for the cleanup process, is increasingly used in Japan. Since this method has hardly been studied for the analysis of pesticides in natural food colorants, it is necessary to evaluate its performance.

Objective: This study aimed to evaluate the applicability of the modified QuEChERS method for the analysis of neonicotinoid insecticides (NEOs) in beetroot and paprika selected from natural colorants.

Methods: The modified QuEChERS method was evaluated by a recovery study using blank beetroot and paprika powder. The matrix effect (ME) was also evaluated in detail for the analysis by the modified QuEChERS and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). These results were compared with those obtained by Japanese official multiresidue method.

Results: The mean recovery, intraday repeatability, and interday reproducibility for the modified QuEChERS were acceptable according to the validation guideline. The MEs for the modified QuEChERS were not particularly strong for the NEOs in the beetroot and paprika even when the isotopically labeled internal standards were not used.

Conclusions: The evaluation of the modified QuEChERS was successfully tested and demonstrated the suitability of this method for the analysis of NEOs in beetroot and paprika.

Highlight: The modified QuEChERS is not only accurate but is also a fast and environmentally friendly method for analyzing NEOs in beetroot and paprika.

Background: A wide range of foods containing genetically modified organisms (GMOs) are commercially available. To verify the accuracy of GMO labeling, real-time PCR is used to quantify GMO content in raw materials. However, DNA fragmentation during food processing can introduce analytical bias, making it difficult to accurately assess GMO content in processed foods.

Objective: This study aimed to establish a method to accurately evaluate food labeling suitability by inferring the GMO content at the raw material stage from the measurement results of processed foods.

Methods: Model processed foods (heat-treated soybeans) containing GM events were prepared and analyzed using a GMO quantification method incorporating taxon-specific real-time PCR with longer amplicons.

Results: We observed that the calculated GMO content increased with the length of the amplicon used in the taxon-specific PCR assay. This finding indicates that GMO content can be artificially influenced by modifying the amplicon size. When a longer amplicon was deliberately employed, the GMO content calculated for the processed food always exceeded that of the raw material.

Conclusion: The use of longer amplicons in taxon-specific PCR can lead to an overestimation of GMO content at the raw material stage based on the measurements from processed foods. If the overestimated value remains below the labeling threshold, the appropriateness of GMO labeling can still be confirmed. The proposed method offers a simplified and practical approach for use in routine inspections.

Highlights: The developed method enables direct analysis of processed foods to assess GMO labeling appropriateness. It eliminates the need to obtain raw materials or conduct multiple analyses. The approach simplifies GMO quantification in inspection laboratories by reducing procedural complexity.

Background: Carbamates have been used in intentional poisoning cases to cause death in both humans and animals. Granulated material containing carbamate pesticides is often applied to the victim's food, water, or drink. Toxicological analysis is essential to confirm such cases.

Objective: This study aims to identify and quantify carbamates (methomyl, aldicarb, propoxur, carbofuran, and carbaryl) present in granular formulations used to adulterate food, through the application of chromatographic and vibrational microspectroscopic techniques.

Methods: Thin layer chromatography (TLC), liquid chromatography with diode array detector (LC-DAD), gas chromatography-mass spectrometry (GC-MS), Attenuated total reflectance Fourier transform infrared (ATR-FTIR), and Raman microspectroscopy were performed. An aliquot of granular formulation was manually separated for chromatographic methods; dilutions were employed as test material treatment, while vibrational microspectroscopy techniques used raw material for toxicological analysis. A material similar to a shredded sausage containing suspected granular formulation was evaluated in chromatographic tests, and carbofuran was determined.

Results: The proposed TLC methodology for identifying carbamates proved unfeasible due to insufficient chromatographic separation. The LC-DAD method was fully validated with success for methomyl, aldicarb, propoxur, carbofuran, and carbaryl, revealing a concentration of 744 µg/g of carbofuran in the suspected material, which was further confirmed by GC-MS. Raman microspectroscopy was not precise enough for carbamate identification, but ATR-FTIR demonstrated high specificity and robustness in identifying carbamate pesticides present in the test material.

Conclusion: This study allowed determining the profile of carbamate pesticides in granular material when present in adulterated food/feed. To isolate the granules manually reduces the carrying of matrix interferents from food and/or feed. Furthermore, the techniques applied require only the raw material or its diluted versions, avoiding steps, high consumption of organic solvents, and reducing analysis time and cost.

Highlights: LC-DAD was successfully validated for multiple carbamates. Minimal test material prep reduces solvent use, analysis time, and costs.

Background: Ivermectin (IVE) is an antiparasitic sold in the form of tablets, pastes, and injectable solutions. Neither the literature nor the official compendiums present an environmentally friendly method for analyzing the final IVE product by thin layer chromatography (TLC) assisted by digital images. This combination strengthens the advantages of cost, handling, time, execution and process optimization. Items, which the green and clean analytical chemistry values, and the National Environmental Methods Index (NEMI), Eco-Scale Assessment (ESA), Analytical GREEnness Metric (AGREE) and Green Analytical Procedure Index (GAPI) tools measure.

Objective: The objective of this work is to develop and validate an eco-efficient, fast, economical and easy-to-perform method for analysis of IVE injectable solution by TLC assisted by digital images.

Method: Silica gel plate, microsyringe and ethyl acetate: ethanol (13:2, v/v) as mobile phase were used in the method. The pixels were analyzed by Image J software after the spots were photographed under UV light.

Results: The method was selective when comparing standard and sample, indicative of stability by forced degradation test, linear (100-900 µg/mL), precise (RSD < 2%), accurate and rugged to modifications in the analytical process. The method was able to quantify commercial products, showing an average content of 98.95%. The greenness of the developed method presented NEMI with 4 green quadrants, ESA and AGREE with a score of 83 and 0.61, respectively, and GAPI predominantly green and yellow.

Conclusions: The method was selective, indicative of stability, linear, precise, accurate, rugged and green, by NEMI, ESA, AGREE and GAPI, to quantify IVE in injectable solution. Additionally, it combined the advantages of TLC and digital image analysis.

Highlights: The work shows a TLC method assisted by digital images for analysis of ivermectin-based product.

Background: Fodder crops are widely used as main ingredients of animal feed products. To combat pest infestations, farmers often apply pesticides on farms, the residual content of which may accumulate at or beyond toxic levels in/on the green fodder at the stage of harvest. To safeguard animals and humans (through ecological food chains) from these residual pesticides, both domestic and commercial programs are necessary to monitor the levels of pesticide residues in food and feed. Nonetheless, the existing methods exhibit constraints regarding scope, selectivity, and sensitivity. These limitations warranted a high-throughput, multiresidue method for monitoring and risk assessment of multiclass pesticides in fodder crops.

Objective: The study aimed to develop and validate a multiresidue method for the simultaneous analysis of 451 multiclass pesticides, their isomers, and metabolites of toxicological concern in three widely used fodder crops, namely sorghum, maize, and lucerne.

Methods: The well-homogenized samples of sorghum, maize, and lucerne (10 g) were extracted with acetonitrile (10 mL). An aliquot of the extract was cleaned by dispersive solid phase extraction (dSPE) with graphitized carbon black (GCB, 7.5 mg/mL). The method performance was evaluated for a mixture of multiclass pesticides at 10 µg/kg and 20 µg/kg using liquid and gas chromatography with tandem mass spectrometry (LC-MS/MS and GC-MS/MS).

Results: The GC-MS/MS and LC-MS/MS techniques allowed analyses of the test pesticides within chromatographic runtimes of 17 min and 20 min, respectively. The method's performance using matrix-matched calibration was satisfactory for all compounds (recoveries = 70-120%, repeatability-RSD, <20%) at 10 and 20 µg/kg in three studied matrices.

Conclusions: The method successfully determined the residues of all tested compounds in each fodder matrix. It demonstrates satisfactory selectivity, accuracy, and repeatability. Given all of these, it is recommended for regulatory and commercial testing purposes.

Highlights: A high-throughput residue analysis method targeting 451 compounds in sorghum, maize, and lucerne involved a single multiresidue extraction, followed by dSPE cleanup with analysis using LC-MS/MS and GC-MS/MS. The method sensitivity met the EU-MRLs, and performance complied with the SANTE/11312/2021's quality control criteria.

Background: Freshness is one of the most important qualities of fish and has a significant impact on utilization and commercial value. As global production and trade volumes of fishery products increase, standardization of scientific methods for evaluating fish freshness is required.

Objective: The K value based on the ratio of ATP derivative content is widely recognized as a scientific freshness index of fish. The aim of this study was to standardize the K value analysis method, which would be useful for fair commercial transactions of bony fish.

Methods: Conventional methods for analyzing K values of fish were modified. An interlaboratory study was conducted to evaluate the reproducibility of the method. The 11 participating laboratories analyzed 10 test samples (five pairs of blind duplicates of material) using HPLC.

Results: For five test materials with a K value of 6.12-83.4%, the range of reproducibility relative standard deviation (RSDR) was 1.3-3.5%. The reproducibility standard deviation (sR) was 0.21-1.2%.

Conclusion: Considering the rate of increase of K value in typical bony fish species and storage conditions, the target value of sR was set to ≤1.25%, so detecting a difference of 5% in K values. The results of the interlaboratory study met this criterion.

Highlights: The precision of the method was found to be acceptable.

Background: Glucose is the most abundant monosaccharide. Glucose is mainly made by plants during photosynthesis from water and carbon dioxide, using energy from sunlight. It is therefore contained in many foodstuffs naturally or added later as an ingredient.

Objective: To validate the performance of the Enzytec™ Liquid D-Glucose for the determination of D-glucose in food and beverages such as fruit and vegetable juices, soft drinks, wines, and beer.

Methods: The kit contains two ready-to-use components, which makes handling easy and suitable for automation. D-Glucose is phosphorylated to glucose-6-phosphate (G-6-P) by a hexokinase and ATP. In the presence of glucose-6-phosphate dehydrogenase and NAD, G-6-P reacts to gluconate-6-phosphate, whereby NADH is formed and measured at a wavelength of 340 nm within 20 minutes.

Results: Mannose and D-fructose interfere at 5.1 and 12.5 g/L (or more), respectively. Sulfite does not interfere up to 1.25 g/L. The calculated LOD and LOQ when using a test solution volume of 100 µL are 1.4 and 4 mg/L, respectively. The linear measurement range is from 4 to 2000 mg/L D-glucose. Trueness was checked by using materials from NIST (cranberry juice) and one reference wine from the German Wine Analysts. Spiking of wine, beer, and juices resulted in recoveries between 93 and 101%. Analysis of NIST SRM 3282 resulted in an intermediate precision of 4.1%. For automation, three applications with different test solution volumes and different but overlapping measurement ranges were validated. Linearity is given from 2.4 up to 10 000 mg/L.

Conclusions: The method is robust and accurate for manual and automated applications. The method was approved as AOAC Official Method of Analysis℠.

Highlights: The ready-to-use components of the test kit have a shelf life of at least 29 months from the date of manufacture.

Background: Miquelianin (MIQ) is a natural phenolic compound found in various plants, including Salvia species, with potential health benefits due to its antioxidant and anti-inflammatory properties.

Objective: This study presents an investigation of the electrochemical oxidation pathway and sensitive analysis of MIQ, which was isolated from the aerial parts of Calystegia silvatica (CS) that grows in Trabzon, Turkey.

Methods: Electrochemical determination methods have gained significant attention for the quantitative analysis of bioactive compounds due to their simplicity, sensitivity, and cost-effectiveness. The electrochemical determination of MIQ primarily involves the utilization of electrochemical techniques such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

Results: Under optimum experimental conditions, a calibration plot for MIQ with LODs of 99.3 × 10-9 M and 145 × 10-9 M were obtained using DPV with glassy carbon electrodes (GCEs) and boron-doped diamond electrodes (BDDEs) in the range of 2.0 × 10-6 to 3.6 × 10-5 M. The presented method was validated and successfully performed for the determination of MIQ from plant extracts with excellent recovery values as 104.7, 101.8, and 102.1%.

Conclusion: This study explores the electrochemical oxidation pathway and sensitive analysis of MIQ, isolated from C. silvatica in Trabzon, Turkey. GCEs and BDDEs as carbon-based electrodes were used for the sensitive analysis of MIQ in phosphate buffer (PB) solution at pH 7.0 solution. MIQ was detected using GCEs and BDDEs with limits of 99.3 × 10-9 M and 145 × 10-9 M, respectively, within a concentration range of 2.0 × 10-6 to 3.6 × 10-5 M. The validated method demonstrated excellent recovery values of 104.7, 101.8, and 102.1% for determining MIQ from plant extracts.

Highlights: This electrochemical method offers promising opportunities for accurate and sensitive analysis of MIQ. Continued research and technological advancements in this field can contribute to a deeper understanding of the electrochemical behavior of MIQ and facilitate its practical applications in pharmaceutical, food, and nutraceutical industries, promoting its utilization as a valuable bioactive compound.

Background: Ivermectin (IVM) is commonly used for the treatment of parasitic diseases in aquaculture and is administered either through oral or immersion methods, but it lacks regulatory approval.

Objective: The aim of the present study was to determine the acute oral toxicity of IVM by estimating the 96 h median lethal dose (LD50) using mortality as endpoint, for an economically important freshwater fish, Cyprinus carpio.

Methods: Medicated feed was prepared by employing different doses of IVM top-dressed onto the commercial feed pellets. A single oral dose of IVM at different doses (mg/kg b.wt.) of 0 (control-T1), 1 (T2), 2.5 (T3), 5 (T4), 10 (T5), 12 (T6), 15 (T7), 18 (T8), 21 (T9), 25 (T10), and 50 (T11) was dissolved in dimethyl sulfoxide (DMSO) and top-dressed using 0.5% w/v guar gum as a wet binder to the feed. The medicated feed was administered at 3% b.wt. to all treatment groups and cumulative mortalities were recorded over a duration of 96 h.

Results: The estimated LD50 of IVM was found to be 8.91 ± 3.46 mg/kg·b.wt. Furthermore, the treatment group (T2) was administered a single oral dose of 1 mg/kg b.wt. and did not exhibit any noticeable behavioral changes compared to the control group. Similarly, LOAEL and NOEAL doses were found to be 2.5 mg/kg b.wt. and 1 mg/kg b.wt., respectively.

Conclusions: This study provides valuable insights for further determining the safe dosage of IVM that can be used in aquaculture for the treatment of parasitic diseases.

Highlights: The present study might be helpful for fixing the maximum residual limit (MRL) for IVM in the aquaculture sector, and the data will be helpful for prescription of the drug by regulatory authorities for treating parasitic diseases in fish.