Journal of AOAC International最新文献

Background: A method for simultaneous determination of six human milk oligosaccharides (HMOs) is described. The HMOs include 2'-fucosyllactose (2'-FL, CAS number 41263-94-9), 3-fucosyllactose (3-FL, CAS number 41312-47-4), 6'-sialyllactose (6'-SL, CAS number 35890-39-2), 3'-sialyllactose (3'-SL, CAS number 35890-38-1), lacto-N-tetraose (LNT, CAS number 14116-68-8), and lacto-N-neotetraose (LNnT, CAS number 13007-32-4). The method was designed to comply with the respective Standard Method Performance Requirements (SMPR®; seeTable 1), respectively.

Objective: The method is valid for six HMOs in infant formula and adult nutritional matrixes, including samples with intact protein, protein hydrolysates, elemental formulations free of intact protein, and rice flour over the ranges defined in the SMPR (seeTable 2). The method is not valid for determination of difucosyllactose (DFL/DiFL).

Method: For most samples, reconstitution with water followed by filtration. For products containing interferences (fructans and maltodextrins), hydrolysis with enzymes is used. After preparation, samples are analyzed using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The method provides for separation of six HMOs and other carbohydrates commonly found in infant formula and adult nutritional products (e.g., lactose, sucrose, and GOS).

Results: This study includes data from multiple matrixes evaluated by multiple laboratories globally. RSDr ranged from 0.0068 to 4.8% RSDr, and spike recovery results ranged from 89.4 to 109%. Calibration fit optimal with a quadratic curve; alternately linear fit showed no statistically significant impact to data (when correlation passes).

Conclusions: This method was reviewed by the AOAC SPIFAN Expert Review Panel (ERP) and determined to meet the SMPRs for the six noted HMOs.

Highlights: The method was granted First Action Official MethodsSM status.

Background: Xiangsha Pingwei Pills (XPP) is a traditional Chinese medicine (TCM) prescription, which is widely used to treat epigastric pain in China. Its systematic chemical characteristics have rarely been reported, which hinders the interpretation of the material basis of its prescription.

Objective: To establish a rapid and effective component characterization method for XPP using ultra-HPLC-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS) and the data post-processing program, Peakview 1.2 software.

Methods: A UPLC-Q-TOF-MS method coupled with Peakview 1.2 software was successfully established for the first time to investigate the complex constituents of XPP. Accurate MS and MS/MS data were detected in positive and negative ion mode. The compounds were tentatively identified based on their retention times, MS, and MS/MS data, as well as reference standards and from the literature.

Results: The chemical profile of XPP was acquired, and a total of 130 compounds in XPP were preliminarily identified for the first time, including 6 organic acids, 59 flavonoids, 13 lignans, 20 terpenoids, 9 phenylpropanoids, 6 alkaloids, 5 amino acids, and 12 other compounds.

Conclusion: A rapid and effective UPLC-Q-TOF-MS method for the main chemical components of XPP has been established for further characterizing constituents and the overall quality control of XPP.

Highlights: This is the first report of a comprehensive analysis method for the main chemical components of XPP, which aims to lay a solid foundation for the chemical basis and overall quality control of XPP.

Background: The fixed-dose combination (FDC) of metoprolol succinate (MTS), cilnidipine (CDN), and telmisartan (TST) is used for the management of hypertension. Numerous reversed phase (RP)-HPLC methods have been reported in the literature for chromatographic analysis of MTS, CDN, and TST. According to the concept of green analytical chemistry (GAC), toxic organic solvents should be avoided or minimized during chromatographic method development for the safety of analysts and the protection of the environment. The reported RP-HPLC methods have been developed using acetonitrile (ACN) or methanol as an organic component of the mobile phase and diluent for sample preparation. These organic solvents are considered toxic solvents as per the International Council for Harmonization (ICH) Q3C (R6) guideline and Pfizer medicinal chemistry solvent selection (PMCSS) guide.

Objective: We aimed to develop an environment-friendly and economical RP-HPLC-photo-diode array (PDA) method for the analysis of MTS, CDN, and TST using less toxic organic solvents to support the concept of GAC.

Methods: The method development was carried out by the implementation of chemometrics and design of experiments (DoE) to avoid wastage of organic solvent. Principal component analysis (PCA) was applied as a chemometric tool for the identification of critical method risk variables (MRVs) and method performance attributes (MPAs). The identified critical MRVs and MPAs were further studied by DoE-based response surface modelling for optimization of the method.

Results: The chromatographic analysis of MTS, CDN, and TST was carried out using a Shim-pack ODS column as a stationary phase and ethanol as an organic modifier in the mobile phase. The developed method was applied to the assay of FDCs and results were found to be in compliance with the label claim. The greenness profiles of reported and present RP-HPLC methods were evaluated by national environmental method index (NEMI) and analytical greenness (AGREE) methods.

Conclusion: The developed method was found to be green, robust, and economical as compared to published methods for the analysis.

Highlights: Development and validation of an RP-HPLC method for simultaneous estimation of MTS, CDN, and TST using safe organic solvents. Implementation of a analytical quality by design (AQbD) approach in method development using PCA and DoE. Application of the method for assay of FDCs of MTS, CDN, and TST.

Background: Argyreia nervosa (Burm. Fil.) Bojer., a woody climber, is indicated in Ayurveda to treat debilities of the male reproductive system, diseases of the nervous system, and chronic ulcers.

Objective: A sensitive analytical method was developed to estimate bioactive scopoletin from methanolic extract prepared from the medicinally active dried roots of Argyreia nervosa (Burm. fil.) Bojer using HPLC equipped with a fluorescence detector.

Methods: Chromatographic separation was achieved using a LunaTM (C18, 250 × 4.6 mm, id: 5 μm) column using an isocratic mobile phase comprising phosphate buffer (pH 3.5)-acetonitrile (80 + 20, by volume) at a flow rate of 1.0 mL/min. The excitation wavelength was 345 nm, and the emission wavelength was 444 nm. The chromatographic parameters were optimized using the design of the experiment approach after determining the combined effects of selected independent variables on area, retention time, and tailing factor (TF) for the peak corresponding to scopoletin, and the experimental design was validated by navigating through the design space.

Results: The developed method was found linear in the range 10-140 ng/mL. The results of the studies confirmed the accuracy, precision, and robustness of the developed analytical method. The plant material was found to contain 0.0125 ± 0.0001% w/w scopoletin on a dried weight basis when estimated using the developed method.

Conclusion: The method was developed using the HPLC-fluoresence detection by adopting the design of experiment approach and simple sample preparation for the estimation of scopoletin from roots of A. nervosa.

Highlight: This extremely sensitive analytical method with one-step sample preparation has the potential to be adapted for routine QC procedures.

Monitoring of food products by government agencies for their compliance to regulatory limits is an essential step in controlling foodborne outbreaks. For monitoring purposes, an extensive setup of the surveillance system is used, which involves ISO 17025:2017 accredited laboratories for food testing. Participation in proficiency testing (PT) programs is a requirement of ISO 17025:2017, which ensures data accuracy and analyst competency. Participation in PT schemes is costly for laboratories in developing countries as most of the commercial suppliers are situated in the United States and Europe. The literature or data available on creation of microbiological proficiency testing is scanty as much of the data available with commercial suppliers are trade secrets, and there is only 0.06% of research articles available in the Scopus database on the topic. In this review article, an attempt is made to understand the factors impacting the survival of two important foodborne pathogens, i.e., Escherichia coli and Salmonella spp., by extracting information available from growth studies and root-cause analysis of various food safety incidents and recalls. Utilization of this information in the development of PT samples is discussed in this review article along with a focus on the availability of PT samples and associated ISO standards to formulate homogeneous and stable PT samples. This review article elaborates on the focus areas that can be considered by PT providers (PTP)-for example, initial inoculum level and preparation, strain type, microbial growth phase, the impact of different types of food matrixes including low-moisture food, antimicrobial components, pH, presence of competitor microbes, and environmental conditions involving storage temperature, time, and relative humidity. These focus areas can be used to successfully create PT samples by PTP in developing countries.

Background: Florfenicol (FF) is a chloramphenicol analogue used in animals, and florfenicol amine (FFA) is the main metabolite of FF. However, their residues in agricultural products are harmful to human health. A highly specific and sensitive assay for FF/FFA detection needs to be developed since the traditional detection methods are low in sensitivity.

Objective: In this study, a new method for rapid quantification of FF/FFA in poultry eggs by helper antibody-based fluorescent immunochromatographic assay (HAFIA) was established.

Methods: Triple antibodies including a primary monoclonal antibody (mAb) specific to the targets FF and FFA, a secondary polyclonal antibody (pAb) labeled with europium nanoparticles (EuNPs), and a helper monoclonal antibody (hAb), reacting with pAb but not with the mAb or the target antigen, are designed, which can form structural aggregation complexes in microwells with a single step of reactions. By loading the reaction sample solution, the triple-antibodies (mAb-pAb-hAb)-EuNPs complexes migrate to the test (T) line on the nitrocellulose membrane of testing strip and are competitively captured by the immobilized FF-bovine serum album (BSA) conjugates on the membrane and the FF/FFA targets in the sample solution.

Results: Fluorescence on the T line is read by a portable fluorescent strip reader in 10 min, and the result is given as the ratio of fluorescent intensities on the T and control (C) lines. This new fluorescent testing strip, with amplified signal from the triple-antibody complex, has 50-fold higher sensitivity than conventional colloidal gold-lateral flow immunoassays (CG-LFIAs), and can detect as low as 0.01 ng/mL FF and 0.1 ng/mL FFA targets from egg samples.

Conclusion: The developed competitive fluorescent immunochromatography method based on auxiliary antibodies has the advantages of high sensitivity and specificity for the rapid and quantitative detection of FF/FFA in poultry eggs.

Highlights: Newly designed helper antibody and portable device were applied to quantitative detection. HAFIA tests egg samples and results can be obtained in 10 minutes. HAFIA has the advantages of being more convenient, faster and does not require professional laboratory personnel.

Background: High-brominated flame retardants (BFRs) can be released into the environment from consumer products, such as electric and electronic equipment, and enter the human body by different pathways. Because of their toxicity and the regulations, it is very relevant to know their levels and trends in human samples. However, chromatographic serum analysis of some of these compounds represents nowadays a challenge in the general population.

Objective: To optimize and validate an instrumental method based on gas chromatography coupled to mass spectrometry, which, together with a simple sample preparation procedure, allows the analysis of decabromodiphenyl ether (BDE-209), decabromodiphenyl ethane (DBDPE), and tetrabromobisphenol A-bis(2,3-dibromopropyl ether) (TBBPA-DBPE) in human serum samples from the general population.

Method: To minimize the high degradation during instrumental analysis, GC parameters such as injection volumes, carrier flow rates, and column lengths were assessed and optimized. This instrumental approach in combination with solid-phase extraction (SPE) followed by multilayer silica gel column purification allowed satisfactory analysis using only 1 mL of serum.

Results: The performance of the complete method was evaluated at three spiking levels, 0.01, 0.05, and 0.2 ng/mL. Recoveries in the range 87-108% were obtained whereas the relative standard deviation in interday measurements, were, in general, lower than 19%. Limits of detection were in the range of 0.0045-0.0070 ng/mL. The optimized procedure was successfully applied to the determination of the investigated pollutants in real human samples of general population.

Conclusions: The proposed method could contribute to the inclusion of these environmental pollutants in human biomonitoring (HBM) studies, increasing the knowledge of levels and trends in the general population.

Highlights: GC-MS parameters optimization to minimize instrumental analytes degradation. Successful application to human serum samples from the general population. Tetrabromobisphenol A bis(2,3-dibromopropyl ether) human serum levels are reported for the first time.

A broad range of AOAC Official Methods of AnalysisSM (OMA) have been developed and approved for the measurement of dietary fiber (DF) and DF components since the adoption of the Prosky method (OMA 985.29). OMA 985.29 and other OMA were developed to support the Trowell definition of DF. However, these methods do not measure DF as defined by the "new," physiologically relevant, Codex Alimentarius definition. Methodology to support the Codex definition has been developed and updated in recent years. In this article, the relevance of each OMA in supporting the Codex definition of DF is described and suggestions are presented on the most appropriate method, together with proposals for changes in title and application statements for the "historic" OMA methods.

Background: Carbendazim is a fungicide which can seep into the water supply, presenting a public health risk, and therefore the accurate trace determination of this substance is very important.

Objective: The purpose of the study is to take a top-down analytical validation approach in order to determine the amount of carbendazim in drinking water by using an SPE-LC-MS/MS technique.

Methods: Quantification of carbendazim using solid-phase extraction coupled with LC-MS/MS was used in order to ensure the accuracy of the analytical method and to control the risk of its routine application. An overall validation methodology based on two-sided tolerance interval type β-content, γ-confidence has been applied for the validation and estimation of uncertainty by building a decision graphical tool called the "uncertainty profile" by using the statistical process known as the Satterthwaite approximation with no recourse to additional data by satisfying intermediate precision condition for each concentration level within the acceptance limits fixed in advance.

Results: The process of validation is based on the selection of a linear weighted 1/X model enabling validation of the carbendazim dosage using LC-MS/MS in the range of working concentrations as the βγ-CCTI fell inside acceptable limits of ±10%, and the relative expanded uncertainty did not surpass 7% regardless of the β values (66.7, 80, and 90%) and the 1- γ = risk (10 and 5%).

Conclusion: The application of the uncertainty profile approach for full validation of a SPE-LC-MS/MS assay for the quantification of carbendazim has been successfully achieved.

Highlights: Implementation of a full validation strategy based on validation and measurement uncertainty with no additional effort using data from analytical validation under intermediate precision conditions at each level of concentration for carbendazim quantification in drinking water using SPE-LC-MS/MS. So we have shown the flexibility of this approach for carbendazim assay by LC-MS/MS. Indeed, It provides an efficient decision-making tool that allows selection and modification of β-content and γ-confidence values.

Background: Food allergen analysis is essential for the development of a risk-based approach for allergen management and labeling. MS has become a method of choice for allergen analysis, even if quantification remains challenging. Moreover, harmonization is still lacking between laboratories, while interlaboratory validation of analytical methods is necessary for such harmonization.

Objective: This interlaboratory study aimed to evaluate the potential of MS for food allergen detection and quantification using a standard addition quantification strategy and a stable isotope-labeled (SIL) concatemer as an internal standard.

Methods: In-house-produced test material (cookies), blank and incurred with four allergens (egg, milk, peanut, and hazelnut), allergen standards, an internal standard, and the complete methodology (including sample preparation and ultra-HPLC-MS/MS method) were provided to nine laboratories involved in the study. Method sensitivity and selectivity were evaluated with incurred test material and accuracy with spiked test material. Quantification was based on the standard addition strategy using certified reference materials as allergen protein standards and a SIL concatemer as an internal standard.

Results: All laboratories were able to detect milk, hazelnut, and peanut in the incurred cookies with sufficient sensitivity to reach the AOAC INTERNATIONAL Standard Method Performance Requirements (SMPR® 2016.002). Egg detection was more complicated due to food processing effects, yet five laboratories reached the sensitivity requirements. Recovery results were laboratory-dependent. Some milk and hazelnut peptides were quantified in agreement with SMPR 2016.002 by all participants. Furthermore, over 90% of the received quantification results agreed with SMPR 2016.002 for method precision.

Conclusion: The encouraging results of this pioneering interlaboratory study represent an additional step towards harmonization among laboratories testing for allergens.

Highlights: In this pioneering interlaboratory study, food allergens were analyzed by MS with characterized incurred and spiked test materials, calibrated with a certified reference material, and a single SIL concatemer used as an internal standard.