Journal of AOAC International最新文献

{"title":"Development of Psilocybe mushroom species reference material-cultivation parameters and chemical profiles.","authors":"Coleton Windsor, Anna E Kreynes, Jeff S Chilton, William A Chioffi, Christopher Niebergall, Kelsey Dodds","doi":"10.1093/jaoacint/qsaf007","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf007","url":null,"abstract":"<p><strong>Background: </strong>Psilocybin-containing mushrooms are gaining the attention of the scientific community due to the potential benefits offered by their psychoactive phytochemicals in the treatment of addiction and various mental health conditions. Although there are hundreds of different Psilocybe species, only a handful have been successfully cultivated under indoor controlled conditions and chemically analyzed.</p><p><strong>Objective: </strong>The goal of this publication is to describe Nammex's ongoing effort to cultivate poorly studied Psilocybe mushroom species and analyze them by High Performance Thin-Layer Chromatography (HPTLC) to identify and quantify important psychoactive compounds.</p><p><strong>Methods: </strong>Pure mycelium cultures of Psilocybe species were created from spore prints and tissue of mushrooms collected in the wild. From these mycelia, numerous cultivars were developed and then propagated on various substrates, based upon nutritionally supplemented cellulosic materials. Using indoor growth chambers under strictly controlled conditions, mushrooms were produced and prepared for analysis.</p><p><strong>Results: </strong>Six Psilocybe species (P. zapotecorum, P. natalensis, P. azurescens, P. subaeruginosa, P. cyanescens, and P. stuntzii) were successfully cultivated indoors. Species identity was confirmed through analysis of anatomical and microscopic features, as well as by DNA sequencing. HPTLC was successfully used to quantify psilocybin and psilocin and identify norbaeocystin, baeocystin, and aeruginascin. P. zapotecorum had the highest psilocybin content (1.89%) and P. stuntzii the lowest (0.45%). Preliminary data showed that psilocybin concentrations remained stable across three successive flushes of P. stuntzii. Storage of fresh mushrooms in -20 °C freezer prior to freeze drying drastically reduced psilocybin and increased psilocin levels.</p><p><strong>Conclusions: </strong>This study successfully demonstrated the cultivation and chemical profiling of multiple Psilocybe species under controlled conditions. The detailed HPTLC analysis revealed species-specific differences in psychoactive compound concentrations. Future research will incorporate advanced techniques, such as HPLC and mass spectrometry, to develop a more comprehensive chemical profile of these mushrooms.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143442794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THC Content on a Dry Weight Basis: Implications for Hemp Legality.","authors":"Frank J Sikora, Solomon K Kariuki, Robert C Pearce, Doris Hamilton, Huihua Ji","doi":"10.1093/jaoacint/qsae048","DOIUrl":"10.1093/jaoacint/qsae048","url":null,"abstract":"<p><strong>Background: </strong>The 2018 Farm Bill defines hemp as Cannabis sativa L. with a tetrahydrocannabinol (THC) concentration not more than 0.3% on a dry weight basis where THC is implied to be total THC (THCTotal) including both acid (Δ9-THCA) and neutral (Δ9-THC) forms.</p><p><strong>Objective: </strong>Effect of temperature and mass were studied to determine the quickest time to prepare fresh hemp suitable for grinding without affecting THCTotal. Proficiency testing program data were also analyzed to compare THCTotal contents on a dry versus wet weight basis.</p><p><strong>Methods: </strong>Fresh hemp of 150 and 400 g were freeze-dried or heat-treated at 50°C, 60°C, and 70°C for various lengths of time up to 72 h. Ground hemp was analyzed for moisture content via AOAC 934.01 and THCTotal via liquid chromatography/mass spectrometer (LC/MS) or gas chromatography with flame ionization detection (GC/FID). A data set analyzed from a proficiency testing program included moisture and THCTotal from 20 to 67 laboratories on 12 analytical samples circulated from 2020 through 2022.</p><p><strong>Results: </strong>The quickest drying time of 24 h occurred at 70°C with 150 g. These conditions did not affect THCTotal content on a dry weight basis. Twelve proficiency testing program analytical samples ranged from 5.8% to 11.4% moisture and 0.144% to 0.399% THCTotal on a wet weight basis. An increase in reported THCTotal on a dry weight basis compared to a wet weight basis ranged from 0.002% to 0.027% with a significant difference occurring in only one analytical sample.</p><p><strong>Conclusions: </strong>Suitable conditions for drying hemp without altering THCTotal content were 24 h at 70°C. Determining residual moisture in oven-dried ground hemp to calculate THCTotal content on a dry weight basis provides no benefit given the minimal difference between contents on dry versus wet weight bases, interlaboratory variability, and terpene volatilization.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"104-111"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141447896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Integrated Strategy for Establishing the Chemical Profile of Premna Microphylla Turcz. Leaves and Metabolites in Vivo.","authors":"Jinhong Cai, Shenghong Guan, Xueli Hu, Xuezhao Chen, Xiaosun Liu, Shouxin Li, Jingkui Tian, Ping Wang, Hua Gu, Xiaoyong Zhang","doi":"10.1093/jaoacint/qsae079","DOIUrl":"10.1093/jaoacint/qsae079","url":null,"abstract":"<p><strong>Background: </strong>Premna microphylla Turcz. (PMT) is a traditional food and medicinal plant, which has been used to treat cure hemostasis, rheumatism, and dysentery. However, there is still a lack of a clear understanding of the chemical profile of PMT and its metabolites in vivo.</p><p><strong>Objective: </strong>To establish a rapid and efficient analytical method for the identification of phytochemicals in PMT and their metabolites in vivo.</p><p><strong>Methods: </strong>First, the fingerprint of PMT was established by HPLC with method validation. Then, the phytochemical composition of PMT leaves was identified using ultra-performance liquid chromatography-quadrupole time-of-flight-tandem mass spectrometry (UPLC-QTOF-MS/MS). Finally, the prototype and correlated metabolites were detected after oral administration in mice to understand the absorption and metabolism of phytochemicals in vivo.</p><p><strong>Results: </strong>The results showed that the established HPLC method for fingerprint evaluation of PMT has good precision, repeatability, and stability. Additionally, a total of 103 phytochemicals were identified in PMT, including mainly flavonoids and terpenoids. Then, 37 prototype components and 20 derived metabolites in vivo were detected.</p><p><strong>Conclusion: </strong>In this study, we constructed a fingerprint method, which has good stability, precision, and repeatability, and the fingerprint of PMT was established. Then, the chemical profile of PMT in vitro and in vivo was determined. The results showed that flavonoids and terpenoids were the main phytochemicals in PMT, and methylation, sulfonation, and dihydroxylation were the main metabolic pathway in vivo.</p><p><strong>Highlights: </strong>The present study provides the phytochemical basis for subsequent study of pharmacological activity.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"62-77"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Secondary Metabolites of Elaeagnus Angustifolia Leaves Based on UPLC-Q-TOF-MS.","authors":"Jinfa Liao, Liyan Liu, Lu Yang, Wei Sheng, Ke Zhang, Bin Zhou, Silin Yu, Yongzhi Yin, Jinhui Wang","doi":"10.1093/jaoacint/qsae017","DOIUrl":"10.1093/jaoacint/qsae017","url":null,"abstract":"<p><strong>Background: </strong>The leaves of Elaeagnus angustifolia, belonging to the Elaeagnaceae Juss. family, are known for their medicinal properties for relieving cough and asthma, as well as treating dysentery and diarrhea.</p><p><strong>Objective: </strong>To establish a rapid qualitative method for the detection of secondary metabolites in leaves of Elaeagnus angustifolia, including the identification and analysis of various secondary metabolites in leaves of Elaeagnus angustifolia.</p><p><strong>Method: </strong>Samples were separated using a Waters ACQUITY H-Class ultra-performance liquid chromatography (UPLC) system (FTN autosampler, quaternary LC pump) and ACQUITY UPLC® BEH C18 column (1.7 μm, 2.1 mm × 100 mm). The flow rate was set to 0.4 mL/min, the injection volume was 1.0 μL, and the column temperature was set to 45°C. The mobile phase was methanol (A) with -0.1% formic acid in water (B). Samples were analyzed by quadrupole time-of-flight mass spectrometry (Q-TOF-MS).</p><p><strong>Results: </strong>A total of 182 different secondary metabolites were detected from 10 varieties of leaves of Elaeagnus angustifolia, including 77 flavonoids, 20 steroids, 7 alkaloids, 15 amino acids, 18 organic acids, and 45 other compound types.</p><p><strong>Conclusions: </strong>A method for the rapid analysis of leaves of Elaeagnus angustifolia by UPLC-Q-TOF-MS was established, and the secondary metabolites in leaves of Elaeagnus angustifolia were identified. The enrichment of secondary metabolites in leaves of different varieties of Elaeagnus angustifolia was clarified.</p><p><strong>Highlights: </strong>The UPLC-Q-TOF-MS method is very fast and possesses a high degree of selectivity, precision, and sensitivity. These findings provide a reliable foundation for the development of medicinal resources derived from Elaeagnus angustifolia leaves.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"90-103"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139992206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development, Validation, and Application of a Fast Sequential Method for Na, K, Ca, and Mg Determination in Hemodialysis Solutions by HR-CS F AAS.","authors":"Flávia E Schwartzhaupt, Leandro Kolling, Wiliam Boschetti, Cássia V Garcia, Márcia M da Silva, Maria Goreti R Vale, Morgana B Dessuy, Andreas S L Mendez","doi":"10.1093/jaoacint/qsae078","DOIUrl":"10.1093/jaoacint/qsae078","url":null,"abstract":"<p><strong>Background: </strong>Hemodialysis solutions are liquid concentrates used during hemodialysis sessions. They are commonly used as a renal replacement therapy.</p><p><strong>Objective: </strong>This study aimed to develop a method to determine Na, K, Ca, and Mg in hemodialysis solutions by high-resolution continuum source flame atomic absorption spectrometry (HR-CS F AAS) using Design of Experiments (DOE).</p><p><strong>Methods: </strong>The combination of the Doehlert Matrix with the desirability function was used to establish a compromise condition in the optimization of the significant variables studied: 60 L/h for acetylene flow rate, 8 mm for burner height, and 0.25% (w/v) and 0.60% (w/v) for Cs and La concentrations. The method was validated by following the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines and parameters, and, as such, the selectivity, linearity, precision, accuracy, and robustness were evaluated.</p><p><strong>Results: </strong>Calibration curves with the ranges of 25-130 mg/L for Na, 1.0-5.0 mg/L for K and Ca, and 0.30-0.70 mg/L for Mg were employed. The method proved to be precise (RSD lower than 2.7%) and accurate (mean recovery data, contemplating the three levels added, were 103.0% for Na, 100.5% for K, 101.3% for Ca, and 101.5% for Mg).</p><p><strong>Conclusions: </strong>The developed method enables the sequential multielement determination of Na, K, Ca, and Mg in a single run. Requiring only one dilution step, this method significantly reduces analysis time for both sample and standard solution preparation and measurement.</p><p><strong>Highlights: </strong>This study presents the first method reported in the literature for multielement determination in hemodialysis solutions, offering an alternative approach to the current European Pharmacopeia method.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Polymerase Chain Reaction (PCR) Method to Detect Emerging Multidrug-Resistant Salmonella Infantis Harboring the pESI Plasmid in Seafood.","authors":"Krishna Veni, Jerusha Stephen, Manjusha Lekshmi, Binaya Bhusan Nayak, Sanath H Kumar","doi":"10.1093/jaoacint/qsae081","DOIUrl":"10.1093/jaoacint/qsae081","url":null,"abstract":"<p><strong>Background: </strong>Salmonella Infantis is an emerging multidrug-resistant pathogen worldwide due to the acquisition of a megaplasmid, plasmid of emerging Salmonella Infantis (pESI). Reported initially in poultry, the distribution of pESI-harboring S. Infantis in other food types, including seafood, is unknown.</p><p><strong>Objective: </strong>This study aimed to develop and optimize a PCR assay for detecting the pESI in Salmonella and non-Salmonella Enterobacterales.</p><p><strong>Methods: </strong>A duplex PCR targeting the hilA gene and a pESI-associated gene of S. Infantis was designed, and the PCR conditions were optimized. The specificity and sensitivity of the assay were established using 119 Salmonella serovars and 51 non-Salmonella bacterial strains.</p><p><strong>Results: </strong>All Salmonella isolates yielded hilA PCR product, while only pESI S. Infantis was positive for both hilA and pESI genes. No amplification product was obtained with the DNA of 51 non-Salmonella bacterial strains. The detection limit of the duplex PCR was 104 CFU/mL of pure culture of pESI S. Infantis. The sensitivity of detection in artificially spiked shrimp meat was 1 CFU/g after 6 h of enrichment in lactose broth, followed by 12 h of selective enrichment in the Rappaport-Vassiliadis medium.</p><p><strong>Conclusion: </strong>The duplex assay will help screen seafood for Salmonella in general and pESI S. Infantis in particular. Given its high sensitivity, the PCR will be a valuable tool for seafood quality assurance. This approach decreases the typical 3-6 day identification time of Salmonella to less than 24 h.</p><p><strong>Highlights: </strong>S. Infantis carrying the highly transmissible megaplasmid (pESI) is a significant food safety concern. Given its rapid geographical spread and high antimicrobial-resistant traits, it is necessary to have a molecular tool that detects pESI-harboring Salmonella. This study successfully developed a duplex PCR assay that simultaneously detects Salmonella enterica and pESI S. Infantis. This molecular tool will help understand the distribution, sources, and spread of the multidrug-resistance (MDR) plasmid in the food environment.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"56-61"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142549819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical Quality by Design-Assisted Eco-Friendly RP-HPLC Method for the Simultaneous Estimation of Artificial Sweeteners in Commercial Food Samples Utilizing a Green Ultrasound-Assisted Extraction Technique: Greenness, Blueness, and Whiteness Appraisal.","authors":"Atyurmila Chakraborty, Kavitha Jayaseelan","doi":"10.1093/jaoacint/qsae085","DOIUrl":"10.1093/jaoacint/qsae085","url":null,"abstract":"<p><strong>Background: </strong>Acesulfame K (E950) and saccharin Na (E954) are commonly utilized synthetic sweeteners that are added to various processed food products to improve the sweet flavor. Environmentally friendly technology must be prioritized when evaluating the artificial sweeteners, as excessive consumption of these sweeteners presents serious health hazards.</p><p><strong>Objective: </strong>The main aim of this study was to develop an analytical quality by design-aided eco-friendly RP-HPLC technique that can detect both acesulfame K and saccharin Na simultaneously, incorporating green analytical chemistry (GAC) principles and white analytical chemistry (WAC), using the ultrasound-assisted extraction (UAE) technique on commercial food samples.</p><p><strong>Methods: </strong>The usage of ethanol was in accordance with eco-friendly ideals due to its ease of use, speed, and lack of environmental impact. Rotatable central composite design (rCCD) was used for method optimization. A mobile phase consisting of an ethanol-1% aqueous acetic acid (1 + 1, by volume) mixture was used and the separation was carried out on a Zorbax column (SB-C18, 150 × 4.6 mm, 5 µm) at a flow rate of 1 mL/min and a detection wavelength of 217 nm.</p><p><strong>Results: </strong>Acesulfame K had a retention time of 1.134 min and saccharin Na of 2.134 min. Acesulfame K and saccharin Na recovery rates varied betweeen different commercially available food samples, ranging from 65 to 102% and 75 to 101%, respectively.</p><p><strong>Conclusion: </strong>At the defined operating point, the developed procedure displays conformity with the previously defined requirements for linearity, accuracy, sensitivity, and repeatability. The most accurate assessments of greenness were produced by the Green Analytical Procedure Index (GAPI), Analytical Eco Scale (AES), and Analytical GREEnness metrics (AGREE) tools. Results from the Red-Green-Blue 12 (RGB 12) algorithm for whiteness and Blue Applicability Grade Index (BAGI) for blueness indicate that the method is very practical, cost-effective, and environmentally friendly.</p><p><strong>Highlights: </strong>The results of this study could pave the way for more eco-friendly and effective AQbD methods to be used in the future for evaluating various sweeteners using green solvents.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"10-22"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142607769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Dual-Gene Detection of Burkholderia gladioli and Subspecies Cocovenenans in Fresh Noodles and Tremella Using CRISPR-Cas12a/Cas13a.","authors":"Xurong Yao, Mansi Luo, Jianzhao Huang, Langjun Zhou, Binbin Zhang, Zhisen Liang, Xiuying Li","doi":"10.1093/jaoacint/qsae084","DOIUrl":"10.1093/jaoacint/qsae084","url":null,"abstract":"<p><strong>Background: </strong>Burkholderia gladioli pv. cocovenenans is a notable foodborne pathogen that poses a significant risk to food safety. Contaminated food requires distinct classification and treatment procedures for non-pathogenic B. gladioli and its pathogenic subspecies cocovenenans. Hence, establishing a rapid and sensitive detection method to distinguish them is necessary.</p><p><strong>Objective: </strong>In this study, we aimed to establish a method combining the CRISPR-Cas12a/Cas13a (Clustered regularly short palindromic repeats-CRISPR associated proteins 12a and 13a) dual system with recombinase-aided amplification for rapid, specific, and sensitive detection of non-pathogenic B. gladioli and pathogenic subspecies cocovenenans in food.</p><p><strong>Methods: </strong>First, an RAA (Recombinase-aided amplification)-CRISPR-Cas12a/Cas13a method was developed, and its feasibility was assessed. Next, specificity was analyzed using 23 strains of B. gladioli and 5 non-target strains. Following this, sensitivity was evaluated by preparing gradient dilutions of B. gladioli pv. cocovenenans bacterial solutions. Finally, real food test samples, including fresh noodles and tremella artificially contaminated with B. gladioli pv. cocovenenans, were utilized for method validation and sensitivity comparison.</p><p><strong>Results: </strong>The established RAA-CRISPR-Cas12a/Cas13a method exhibited high specificity and achieved 100% accuracy in detecting species B. gladioli and its subspecies cocovenenans. This rapid method could be finished within 45 min with a detection limit of 100 CFU/mL (Colony-forming units per millilter) for bacterial concentration. Additionally, it achieved detection limits of 102 CFU/g for fresh noodles and 103 CFU/g for tremella.</p><p><strong>Conclusion: </strong>The rapid RAA-CRISPR-Cas12a/Cas13a method demonstrated high specificity and sensitivity in detecting and distinguishing species B. gladioli and subspecies cocovenenans in both food test samples and post-cultivation colonies.</p><p><strong>Highlights: </strong>The RAA-CRISPR-Cas12a/Cas13a method presented in this study offers a novel molecular approach for the rapid, accurate, and sensitive detection of B. gladioli and its subspecies cocovenenans in foods.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"116-122"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142607774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"End Column Reverse Chromatography as a Novel Approach for Enhanced Separation: A Pilot Study.","authors":"Mostafa Soliman","doi":"10.1093/jaoacint/qsae080","DOIUrl":"10.1093/jaoacint/qsae080","url":null,"abstract":"<p><strong>Background: </strong>Currently, the most popular technique in gas chromatography (GC) is \"temperature programming,\" where the temperature increases from the start of the injection. This leads to faster elution of analytes compared to isothermal methods. However, isothermal methods are considered optimal for separating compounds with similar retention times. Another interesting technique that provides higher resolution is dynamic thermal gradient gas chromatography (TGGC), where separations are achieved as a decreasing thermal gradient. This gradually decreases the positive gas velocity. Nevertheless, it was proven that GC techniques with negative velocity gradients do not improve the resolution of compounds with nearly identical retention times.</p><p><strong>Objective: </strong>Optimizing a new GC approach to combine both the short time from positive temperature ramps programming, and the enhanced separation of the negative ramps of the TGGC, a model under the name of \"end column reverse chromatography\" (ECRC).</p><p><strong>Methods: </strong>The process simply consists of two steps: the first is a normal positive ramp from the start of the injection, and the second step is a negative thermal ramp at a time that is around the retention time of the first eluting peak. This will decrease the solute velocity almost solely for the second compound, leading to relatively enhanced separation.</p><p><strong>Results: </strong>The optimized ECRC method increased the resolution of two isomers (trans- and cis-chlordane) from 1 (slightly overlapping) in the case of temperature programming to 2.78 as shown in this study. This comes at the expense of the width and intensity of the peaks, where the intensity decreased about 17 and 12% for cis- and trans-chlordane, and the peak width increased with 37 and 77% for the same compounds, respectively.</p><p><strong>Conclusions: </strong>ECRC is a novel model for enhanced separation that comes with some drawbacks.</p><p><strong>Highlights: </strong>It can be an alternative approach to get a fast GC method with enhanced separation for isomers.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"112-115"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of Enzytec™ Liquid Citric Acid for Enzymatic Determination of Citric Acid in Selected Foods and Beverages: First Action 2024.02.","authors":"Markus Lacorn, Thomas Hektor","doi":"10.1093/jaoacint/qsae075","DOIUrl":"10.1093/jaoacint/qsae075","url":null,"abstract":"<p><strong>Background: </strong>Due to its excellent acidifier, antioxidant, and preservative properties, citric acid is added to or is a constituent in a broad range of foods and beverages. Its measurement should be performed to assure the food quality specifications are met.</p><p><strong>Objective: </strong>To validate the performance of the Enzytec™ Liquid Citric acid test kit for the determination in food and beverages such as wines, juices, and tomato products.</p><p><strong>Methods: </strong>The kit contains two ready-to-use components, which makes handling very easy and suitable for automation. Citrate is cleaved into oxaloacetate and acetate by citrate lyase. Oxaloacetate reacts to L-malate by L-malate dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH). Pyruvate, spontaneously formed from oxaloacetate, is converted by L-lactate dehydrogenase to L-lactate. The NADH consumed is equivalent to the amount of citric acid converted and is measured at a wavelength of 340 nm within 20 min.</p><p><strong>Results: </strong>The test is specific to citric acid and shows no relevant interferences. Limit of detection and limit of quantification are 15 and 40 mg/L, respectively when using a test volume of 100 µL. The linear measurement range is from 40 to 1000 mg/L citric acid. Trueness was evaluated using materials from FAPAS, NIST, LGC, and two control wines from the German Wine Analysts. Matrix interference was evaluated by spiking tomato ketchup, tomato paste, orange juice, and carbonated beverages and resulted in recoveries around 100%. Intermediate precision is between 6.2 and 8.5% for matrixes with extraction and below 4% for matrixes measured directly. For automation, three applications with different test volumes and different measurement ranges were validated. Linearity is given from 8 mg/L up to 5 g/L (depending on the test volume).</p><p><strong>Conclusions: </strong>The method is robust and accurate for manual and automated applications. The method was approved as an AOAC Official Method of Analysis℠.</p><p><strong>Highlights: </strong>The ready-to-use components of the test kit have a shelf life of at least 24 months from the date of manufacture.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"29-46"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11761966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}