Journal of AOAC International最新文献

Background: In December 2021, the BIOFISH 300 SUL method for the determination of total sulfites in shrimp was adopted as a First Action Official Method of AnalysisSM by the AOAC INTERNATIONAL.

Objective: A collaborative study was conducted in February 2023 in order to test the reproducibility of the method.

Methods: The method is based on the use of a benchtop biosensor device that relates the concentration of sulfite to a quantifiable electric current signal. The sensing element, the Biotest, harbors an enzyme that specifically oxidizes sulfite, and the reaction products are electrochemically detected by the device in less than 3 min. The sulfite is extracted from the solid using an aqueous-based buffer solution, which ensures that all sulfite is present as a free anion.

Results: Eleven collaborators participated in the study of nine different shrimp samples. Values of repeatability and reproducibility relative standard deviation (RSDr and RSDR) obtained from the statistical analysis of valid data ranged from 2.1-8.1% and 7.5-14.3%, respectively, for shrimp samples above the quantification limit of the method, set at 7 mg/kg.

Conclusion: These results showed good repeatability and reproducibility of the method, even at concentrations below the legal threshold for sulfite in food, where the reference optimised Monier-Williams (OMW) method shows relatively high imprecision.

Highlights: On the basis of these results, the enzymatic amperometric biosensor method developed by BIOLAN Microbiosensores was adopted as Final Action Official Method in September 2023.

Background: Reproducibility has been well studied in the field of food analysis; the RSD is said to follow a Horwitz curve with certain exceptions. However, little systematic research has been done on predicting repeatability or intermediate precision.

Objective: We developed a regression method to estimate within-laboratory SDs using hierarchical Bayesian modeling and analyzing duplicate measurement data obtained from actual laboratory tests.

Methods: The Hamiltonian Monte Carlo method was employed and implemented using R with Stan. The basic structure of the statistical model was assumed to be a Chi-squared distribution, the fixed effect of the predictor was assumed to be a nonlinear function with a constant term and a concentration-dependent term, and the random effects were assumed to follow a lognormal distribution as a hierarchical prior.

Results: By analyzing over 300 instances, we obtained regression results that fit well with the assumed model, except for moisture, which was a method-defined analyte. The developed method applies to a wide variety of analytes measured using general principles, including spectroscopy, GC, and HPLC. Although the estimated precisions were within the Horwitz ratio criteria for repeatability, some cases using high-sensitivity detectors, such as mass spectrometers, showed SDs below that range.

Conclusion: We propose utilizing the within-laboratory precision predicted by the model established in this study for internal QC and measurement uncertainty estimation without considering sample matrices.

Highlights: Performing statistical modeling on data from double analysis, which is conducted as a part of internal QCs, will simplify the estimation of the precision that fits each analytical system in a laboratory.

Background: Microlab Salmonella is an all-in-one solution for detection of Salmonella O Groups A-E that integrates, in a single disposable device, all elements to perform the analysis: a ready-to-use enrichment broth, a lateral flow immunochromatography test, and a chemical agent for bacterial inactivation. Microlab Salmonella can be easily used on-site and does not require specific laboratory equipment or technical skills. The device is sealed during the analysis, avoiding risks of contamination, and is therefore safe to use in food production environments.

Objective: This report details the method validation study for raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, deli ham, and pasteurized liquid egg.

Methods: Matrix studies and inclusivity/exclusivity, product consistency/stability, and robustness testing were conducted to assess the method's performance.

Results: Inclusivity/exclusivity testing showed that the Microlab Salmonella method was able to detect Salmonella O Group A-E isolates while excluding the non-Salmonella strains. In the matrix studies, the differences between the candidate and reference methods were not statistically significant. Minor variations in test parameters (enrichment time, time to read results, and enrichment temperature) did not affect the performance of the Microlab assay. There were no statistically significant differences between recently manufactured lots and those that were halfway through their expiration period or between those that were close to expiring.

Conclusions: The reported data confirm that Microlab Salmonella is reliable for detecting Salmonella in raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, pasteurized liquid egg, and deli ham.

Highlights: Microlab Salmonella is validated to detect Salmonella in select food matrixes. Microlab Salmonella integrates the steps of enrichment, detection, and inactivation in a single device.

Background: The formation of charge-transfer complexes (CTCs) of iodine with five chemotherapeutic drugs used for the treatment of different types of cancer has not been investigated. These drugs are olaparib, seliciclib, vandetanib, dasatinib, and tozasertib. Additionally, these drugs need an appropriate general spectrophotometric assay for their analysis in the dosage forms regardless of the differences in their chemical structures.

Objective: The aim of this study was the development of a novel microwell spectrophotometric assay (MW-SPA) for one-step determination of these drugs via their interactions with iodine, which resulted in instantaneous production of bright lemon-yellow CTCs.

Methods: A spectrophotometric study of the CTCs was conducted, and all CTCs were characterized. Site(s) of interaction on each drug were assigned, and the MW-SPA was developed and applied to the analysis of dosage forms.

Results: The findings confirmed that the reactions proceeded via CTC formation. Beer's law was obeyed over a general concentration range of 1-6 µg/mL. The LODs and LOQs were in the ranges of 0.5-2.1 and 1.5-6.4 µg/mL, respectively. The proposed MW-SPA demonstrated excellent precisions as the relative standard deviations were < 2.24 and 2.23% for the intra- and inter-assay precision, respectively. Recovery studies demonstrated the accuracy of MW-SPA. Successful determination of all drugs in bulk and tablet forms was achieved using the MW-SPA. The environmental sustainability of the proposed methodology was determined, providing evidence of the assay's alignment with the basis of green analytical chemistry. The high throughput of the assay was documented.

Conclusion: In contrast to other existing methods, the MW-SPA described herein was valid for analyzing all drugs at the same wavelength.

Highlights: The assay is useful for routine analysis of drugs in their formulations in QC laboratories.

Background: Intestinal coccidiosis is a debilitating disease in poultry and livestock, leading to economic impact worldwide. Coccidiosis is prevented and treated in broilers by the inclusion of anticoccidials in feed. Toltrazuril is administered in potable water to treat coccidiosis.

Objective: Three robust analytical methods for the quantitation of toltrazuril in pure and pharmaceutical formulations are developed. Furthermore, ecological metrics, either penalization- or color-code-based techniques, are applied for the appraisal of assays.

Methods: First, second-derivative (Δλ; 5 nm) spectrophotometric method is used. Toltrazuril is measured from peak to peak at 244-260 nm within a linearity range of 5-25 μg/mL. The second method is an HPTLC analysis performed on an aluminum sheet of silica gel using ethyl acetate-methanol-ammonium chloride buffer-water (8:1:0.5:0.5, by volume respectively) as the elution phase. Toltrazuril, at a retardation factor of 0.66 ± 0.01, is linearly determined in the range of 1-9 μg/spot at 243 nm. The third method is reversed-phase HPLC with diode array detection, using an Agilent C18 column (5 μm, 4.6 × 150 mm) in isocratic elution mode at 1 mL/min flow rate with a mobile phase of acetonitrile and water in a ratio of 80:20 (v/v). Toltrazuril elutes at a retention time of 2.58 ± 0.1 min and is linearly determined at 243 nm in the range of 0.25-25 μg/mL.

Results: Calculated 2D-values and peak areas are highly correlated to their corresponding drug concentrations at coefficients: r > 0.999. All methods were International Council of Harmonization (ICH) validated and applied to the dosage form with satisfactory % recoveries (97-103%). Statistical comparisons versus reported one using t-test and F-test disclose insignificant variation. In examining greenness and whiteness norms, the proposed methods were evaluated and ranked alongside four different reported methods.

Conclusions: The proposed methods are green, accurate, and can be applied in routine QC for the determination of toltrazuril in pharmaceutical formulations.

Highlights: Intestinal coccidiosis substantially affects the chicken intestinal tract leading to reduced growth. Toltrazuril is used for the treatment and prevention of intestinal coccidiosis. Three robust, accurate, and precise analytical methods are developed for toltrazuril determination in pure and pharmaceutical formulations. All proposed methods were ecologically assessed and compared with published ones.

Background: Reboxetine (RBX) is the first FDA-approved antidepressant drug of the selective noradrenaline reuptake inhibitors class. There is a serious need for a convenient analytical tool for the quantitation of RBX in its dosage form.

Objective: This study aims toward the development and validation of two green and high-throughput microwell spectrometric platforms for the pharmaceutical analysis of RBX.

Methods: The two platforms, abbreviated as MW-AB and MW-FL, involved microwell-based analysis assisted with a multifunction microplate plate reader for measuring absorbance and fluorescence signals, respectively. The MW-AB and MW-FL platforms involved the formation of colored and fluorescent derivatives upon the reaction of RBX with oxidized pyrocatechol reagent (OPC) and tetracyanoquinodimethane (TCNQ), respectively. The absorbance of colored RBX-OPC derivative at 520 nm, and the fluorescence of RBX-TCNQ charge transfer complex at 283 and 484 nm for excitation and emission, respectively. The optimum conditions of both reactions were established, their molar ratios were determined, and reaction mechanisms were postulated.

Results: Both platforms were optimized and validated according to the guidelines of the International Council on Harmonization. The limits of quantitation were 19.6 µg/mL and 27 ng/mL for MW-AB and MW-FL, respectively. Both platforms were applied with excellent reliability to the quantitation of RBX content in Edranox® tablets and their drug uniformity. The greenness levels of both platforms were assessed by two comprehensive tools, and the results confirmed the high level of greenness for both platforms.

Conclusions: Both platforms involved one-step reactions, adapted microwell analysis, and simultaneous handling of large number of samples. Therefore, they have the advantages of greenness and high-throughput analysis.

Highlights: The proposed two platforms are valuable tools for the rapid quantitation of RBX.

Background: Taurine (2-aminoethanesulfonic acid) is an essential β-amino acid, which is one of the most abundant intracellular amino acid component in humans. The level of free taurine in human milk is higher than in bovine milk. Since taurine is considered important for the development of a newborn, fortification of infant nutrition with taurine is common. This publication describes a rapid method for the determination of taurine in infant formula and adult/pediatric nutritionals.

Objective: This publication demonstrates the suitability and applicability of the method to determine taurine content in infant formula and adult/pediatric nutritionals.

Methods: Test portions are deproteinized by acid in an aqueous environment prior to analysis. The level of taurine is analyzed by hydrophilic interaction chromatography (HILIC) coupled with multiple reaction monitoring MS (MRM-MS). Quantitation is accomplished using a stable isotope-labeled internal standard (SILS) for taurine.

Results: The accuracy of the method was validated using standard reference materials and spike recovery studies. The average recoveries ranged between 92% and 105%. The relative standard deviation repeatability (RSDr) and relative standard deviation intermediate precision (RSDiR) were in the range of 0.7-4.6% (RSDr) and 1.3-6.7% (RSDiR). The limit of quantitation (LOQ) was below the requirement of 0.5 mg/100 g.

Conclusion: The single-laboratory validation (SLV) of the method for determination of taurine content in infant formula and adult/pediatric nutritionals demonstrates that it meets the requirements per AOAC INTERNATIONAL Standard Method Performance Requirements (SMPR) 2014.013.

Highlights: A fast method to selectively determine the content of taurine in infant formula and adult/pediatric nutritionals was evaluated and found to be fit for purpose for routine product compliance testing. Based on the results of this SLV, the method was approved by the AOAC Stakeholder Program on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel for SPIFAN Nutrient Methods for First Action Official MethodsSM status.

Background: Aflatoxins (AFs) are toxic metabolites produced by Aspergillus spp. Because AFs are potent carcinogens in humans and animals, many countries have set regulatory limits for AFs in foods to prevent dietary exposure. From a global food safety perspective, in 2023, the Codex Alimentarius Commission established the maximum level (ML) of total AFs in certain cereals and cereal-based products, including polished rice. Therefore, validated analytical methods for AFs detection are necessary.

Objective: In this study, an HPLC-fluorescence method coupled with multifunctional column cleanup and trifluoroacetic acid derivatization was developed for the determination of AF levels in polished rice.

Methods: Our method was validated in a single-laboratory study using AF-spiked materials, followed by an inter-laboratory validation study. Twelve laboratories participated in the inter-laboratory validation study, and five polished rice test samples artificially contaminated with AFs were analyzed.

Results: In a single-laboratory study, the ranges of mean recoveries of AF B1, B2, G1, G2, and total AFs were 101, 100-103, 93-96, 95-98, and 97-99%, respectively. The RSDs for within-day and between-day variations were all ≤4.4%. In the inter-laboratory validation study, the RSDs for repeatability and reproducibility were from 0.7 to 2.7% and 3.3 to 8.9% for all analytes, respectively.

Conclusion: In response to the Codex ML and method performance criteria for AFs in polished rice, an analytical method based on HPLC-fluorescence detection was developed. All method performance parameters estimated from the test results of the single-laboratory and inter-laboratory validation studies met the criteria required by the Codex.

Highlights: Single- and inter-laboratory studies for the validation of an analytical method for AF level determination in polished rice were successfully performed. This analytical method will be suitable to determine AF levels around the Codex ML set for polished rice.

Background: Mercury intake is caused by eating seafood, such as tuna and other predatory fish species. To reduce the health risks of mercury intake, it is necessary to continuously measure and monitor mercury concentrations at fish farms and markets. We have developed a compact system that can detect multiple heavy metals by liquid asymmetric-electrode plasma optical emission spectroscopy (LAEP-OES).

Objective: The validity of the LAEP-OES method for total mercury levels was evaluated using standard solutions, certified substances, and specimens of bluefin tuna and other fish species.

Methods: All specimens were dissolved in 4 M lithium hydroxide solution and then dispensed into a sample reservoir well of the single-use measurement reagent pack. Total mercury levels were automatically measured within 15 min of placement into the dedicated equipment. A total of 102 fish specimens, classified into 10 fish species, were evaluated using the new method and the results were compared to those obtained from validated analytical methods.

Results: LOD (0.02 mg/kg), LOQ (0.07 mg/kg), repeatability (4.0%), intermediate precision (9.8%), and trueness (recoveries 107%) of the proposed method were within satisfactory limits for total mercury levels in fish. Additionally, when using various fish species, the method had a strong positive correlation with the results of cold-vapor atomic absorption spectrometry (CV-AAS, the official method) with Spearman rs = 0.984.

Conclusion: The LAEP-OES method can be used for measuring total mercury levels in bluefin tuna. Total mercury measurement using this new method has the potential to be applied to other fish species.

Highlights: Total mercury levels in fish were measured using our unique analysis system. Pacific bluefin tuna, southern bluefin tuna, and Atlantic bluefin tuna distributed in the Japanese market were analyzed for total mercury in their wild and farmed fish varieties.

Background: Class-I residual solvents such as 1,1-dichloroethene, 1,1,1-trichloroethane, carbon tetrachloride, benzene, 1,2-dichloroethane are toxic, environmental hazards, and carcinogenic to humans. A headspace-gas chromatography-mass spectrometer is a sophisticated instrument for the quantification of residual solvents at lower limits.

Objective: An exact, sensitive, reliable, and fast method was developed to determine 1,1-dichloroethene, 1,1,1-trichloroethane, carbon tetrachloride, benzene, and 1,2-dichloroethane present in different drug substances using a headspace-gas chromatography-mass spectrometer.

Methods: Helium is used as a carrier gas. N-methyl-2-pyrrolidone is used as a diluent, and the stationary phase is a DB-624 (60 m × 0.25 mm × 1.4 μm film thickness) column with a flow rate of 1.5 mL/min.

Results: The concentration LODs for 1,1-dichloroethene, 1,1,1-trichloroethane, carbon tetrachloride, benzene, and 1,2-dichloroethane were 0.24, 5, 0.12, 0.06, and 0.15 ppm. The concentrations LOQs for the aforementioned impurities were 0.8, 15, 0.4, 0.2, and 0.5 ppm. The linearity was assessed over the range from LOQ to 120% of the specification level.

Conclusion: The current method's system suitability, precision, linearity, and accuracy parameters were assessed in accordance with the United states pharmacopeia (USP) < 1225> and International Conference on Harmonization of technical standards for the registration of medicines for human use (ICH) Q2(R2), and the results were within the acceptance criteria.

Highlights: No research studies have been reported on determining class-I residual solvents in lincomycin hydrochloride, dapagliflozin, vonoprazan fumarate, and telmisartan drug substances. The proposed research aims to develop a common method for the quantification of class-I residual solvents for drug substances. The quality by design (QbD) concept is utilized in performance verification.