Determination of Ethanol Content in Kombucha Products by Gas Chromatography with Flame Ionization Detection: A Multilaboratory Study

2019 ◽  
Vol 102 (3) ◽  
pp. 878-882 ◽  
Author(s):  
Ying Liu ◽  
Michael Chan ◽  
Ebersole Blake ◽  
Hong Sy ◽  
Paula N Brown

Abstract Background: Kombucha is a nonalcoholic, fermented tea beverage that has recently received negative attention because of documented concentrations of ethanol in excess of allowable limits of ≥0.5% alcohol by volume (ABV). Objective: Our previously reported headspace GC with flame-ionization detection (GC-FID) method was adopted by the AOAC Expert Review Panel as First Action Official MethodSM 2016.12 in September 2016 based on published single-laboratory validation study results. This paper describes the corresponding multilaboratory study using this method to further validate its performance parameters. Methods: Four laboratories participated in the study and received practice samples, test samples, reference standards, and detailed protocols. Eight kombucha samples sent out to laboratories were randomly assigned sample numbers and were blinded in terms of content and identity. Each laboratory analyzed all samples using the GC-FID method and reported their results. Results: Cochran’s C-test and single and double Grubbs’ tests were used to identify and remove outliers. Horwitz ratio values for all samples were between 0.5 and 1.7. As per the Standard Method Performance Requirements (SMPRs®), all samples within the analytical range of 0.1–2.0 ABV% had RSDR values <6%. Conclusions: The results from this study demonstrate the evaluated GC-FID method meets the SMPR requirements and is fit for purpose for detecting ethanol in kombucha products. Highlights: Kombucha, a nonalcoholic, fermented beverage, has been found to contain ≥0.5% ABV. First Action Official Method 2016.12, a headspace GC-FID method for determining ethanol in kombucha, is supported by a multilaboratory study.

2018 ◽  
Vol 101 (6) ◽  
pp. 1881-1894 ◽  
Author(s):  
Sneh D Bhandari ◽  
Ming Gao ◽  
John Szpylka ◽  
N Collopy ◽  
H Chen ◽  
...  

Abstract Background: The need for an updated reference method for folate was identified as a priority by the AOAC’s Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) in 2011. An Expert Review Panel (ERP) found AOAC Official MethodSM 2011.06 suitable for the purpose and approved it as a First Action Official Method. Objective: To determine the repeatability and reproducibility of Method 2011.06: Total Folate in Infant Formula and Adult Nutritionals by Trienzyme Extraction and LC-MS/MS Quantitation. Methods: A multilaboratory collaborative study was conducted. Eleven laboratories located in five countries participated and completed analysis of all multilaboratory testing (MLT) samples. The study was divided into two parts. In the first part, the laboratories analyzed two practice samples (blindly coded) using the updated folate Method 2011.06. The laboratories providing results within the expected range qualified for part two, in which they analyzed 11 MLT samples in blind duplicates. Results: The results were compared with the Standard Method Performance Requirements (SMPR 2011.006) established for folate. The precision results met the requirements stated in the SMPR for all of the samples. Repeatability and reproducibility relative standard deviations ranged from 3.5 to 6.6 and from 9.0 to 15.7%, respectively. Horwitz ratio values for all of the samples were well below 2 (0.61–1.06). Conclusions: The ERP determined that the method performance met the SMPR requirements in September 2017 after reviewing the presented MLT data. Highlights: The ERP recommended the method for Final Action status.


2019 ◽  
Vol 102 (2) ◽  
pp. 564-569
Author(s):  
Greg Jaudzems ◽  
Fengxia Zhang ◽  
Wu Bolong ◽  
Lei Bao ◽  
Jing Xiao

Abstract Background: In September 2015, both AOAC Official Methods 2015.07and 2015.08 single-laboratory validations (SLVs) were reviewed against Standard Method Performance Requirements® (SMPR) 2014.015by the AOAC Stakeholder Panel for Infant Formula andAdult Nutritional (SPIFAN) Expert Review Panel (ERP). Looking at the similarity and uniqueness of the two methods, the authors agreed, as advised by the ERP, to work together to merge the two methods intoone. This combined method was assigned Method 2016.03. Objective: In order to determine the repeatability and reproducibility of the AOAC First Action 2016.03 method, a collaborative study was organized. The study was divided in two parts: (Part 1) method set up and qualification of participants and (Part 2) collaborative study participation. During Part 1, each laboratory was asked to analyze two practice samples. The laboratories that provided results within a range of expected levels were qualified for Part 2, during which they analyzed 25 samples in blind duplicates. Results: The results were compared with SMPR 2014.015 established for chloride. The precision results (repeatability and reproducibility) were within therequirements stated in the SMPR. In general, the precision results (repeatability and reproducibility)were well within the limits stated in the SMPR. Repeatability ranged from 0.4 to 1.9%, in accordance with data obtained during SLV, with reported RSD of repeatability from 0.03 to 1.6%. Meanwhile, reproducibility ranged from 0.6 to 4.0%. Finally, the Horwitz ratio values were all below 1, from 0.2 to 0.9%. Conclusions: The ERP determined that the data presented met the SMPR and accordingly recommended the method to be granted Final Actionstatus. In January 2018, the Official Methods Boardapproved the method as Final Action.


2016 ◽  
Vol 99 (1) ◽  
pp. 53-54
Author(s):  
Sharon L Brunelle

Abstract A previously validated method for determination of chondroitin sulfate in raw materials and dietary supplements was submitted to the AOAC Expert Review Panel (ERP) for Stakeholder Panel on Dietary Supplements Set 1 Ingredients (Anthocyanins, Chondroitin, and PDE5 Inhibitors) for consideration of First Action Official MethodsSM status. The ERP evaluated the single-laboratory validation results against AOAC Standard Method Performance Requirements 2014.009. With recoveries of 100.8–101.6% in raw materials and 105.4–105.8% in finished products and precision of 0.25–1.8% RSDr within-day and 1.6–4.72% RSDr overall, the ERP adopted the method for First Action Official Methods status and provided recommendations for achieving Final Action status.


2013 ◽  
Vol 96 (4) ◽  
pp. 798-801 ◽  
Author(s):  
Lawrence H Pacquette ◽  
Alan M Levenson ◽  
Joseph J Thompson ◽  
Dawn Dowell

Abstract After an assessment of data generated from a single-laboratory validation study published in the Journal of AOAC INTERNATIONAL 95, 169–176 (2012), a method for determining the total level of iodine in infant formula and nutritional products was presented for consideration for adoption by AOAC during the AOAC Annual Meeting held September 30–October 3, 2012 in Las Vegas, NV. An Expert Review Panel on Infant Formula and Adult Nutritionals concluded that the method met the established standard method performance requirements, and approved the method as AOAC Official First Action. The method involves digestion of the sample with nitric acid in a closed vessel microwave oven, followed by determination by inductively coupled plasma/MS using tellurium as the internal standard. The method LOQ for total iodine was 1.5 μg/100 g, but a practical LOQ was used at 5 μg/100 g total iodine. The analytical range of the method was 5–100 μg/100 g total iodine. The recoveries from 15 spiked nutritional products ranged from 90 to 105%.


2019 ◽  
Vol 102 (5) ◽  
pp. 1574-1588 ◽  
Author(s):  
Greg Jaudzems ◽  
Joseph Guthrie ◽  
Sabine Lahrichi ◽  
Christophe Fuerer

Abstract Background: An acid hydrolysis ultrahigh-performance LC–UV method was evaluated for the determination of total amino acids in infant formula and adult/pediatric nutritional formula. Objective: It was assessed for compliance against AOAC INTERNATIONAL Standard Method Performance Requirements (SMPR®) established by the Stakeholder Panel for Infant Formula and Adult Nutritionals (SPIFAN). Methods: A single-laboratory validation (SLV) study was conducted as a first step in the process to validate the method. In this SLV, 17 SPIFAN matrices representing a range of infant formula and adult nutritional products were evaluated for their amino acid content. Results: The analytical range was found to be within the needs for all products; some may require a dilution. Evaluation of trueness performed on Standard Reference Material 1849a (Infant/Adult Nutritional Formula) showed all compounds met the SMPR theoretical value, with exceptions for threonine and tyrosine. These may have a bias for the National Institute of Standards and Technology (NIST) data, depending on hydrolysis used in the determination of the NIST certificate of analysis. Conclusions: Based on the results of this SLV, this method met the SMPR and was approved as a First Action method by the AOAC Expert Review Panel on Nutrient Methods on August 28, 2018.


2012 ◽  
Vol 95 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Donald L Gilliland ◽  
Charles K Black ◽  
James E Denison ◽  
Charles T Seipelt ◽  
Dawn Dowell

Abstract During the “Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting” held on June 29, 2011, an Expert Review Panel (ERP) on behalf of AOAC INTERNATIONAL adopted the method “Simultaneous Determination of Vitamins D2 and D3 by LC-MS/MS in Infant Formula and Adult Nutritionals” as an AOAC Official First Action method. Vitamins D2 and D3 are extracted from the sample using pentane–ether; the extract is collected and dried under nitrogen. Vitamin D is separated from interfering compounds using UPLC, and quantitated using tandem mass spectrometry (MS/MS). Preliminary data showed the intermediate precision ranged from 3.34–8.05% and an accuracy range of 98.5–111% over the samples tested for vitamin D3. For vitamin D2, the intermediate precision ranged from 2.37–5.45% and accuracy ranged from 96.4–104% over the four matrixes evaluated. The analytical range for the method is bounded by the concentrations of the working standards, 21–270 ng/mL, and is equivalent to 0.168–2.16 mcg/100 g in ready-to-feed product. The practical method quantitation limit is 0.168 mcg/100 g product with method detection limit of 60 ng/100 g product. The ERP reviewed the data and determined that the performance characteristics of the method met the standard method performance requirements, and therefore the method was granted First Action status.


2013 ◽  
Vol 96 (6) ◽  
pp. 1400-1406 ◽  
Author(s):  
Kassandra Oates ◽  
Lillian Chen ◽  
Brian De Borba ◽  
Deepali Mohindra ◽  
Jeffrey Rohrer ◽  
...  

Abstract Single-laboratory validation (SLV) data from a method for the determination of choline in infant formula and adult nutritionals by ion chromatography (IC) and suppressed conductivity were generated and presented to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) at the AOAC Annual Meeting held in Las Vegas, NV, during September 30 to October 3, 2012. The ERP reviewed the data and concluded that the data met the standard method performance requirements (SMPRs) established and approved the method as AOAC Official First Action. At the ERP's request, a second, full SLV was performed on 17 SPIFAN matrixes that included fortified and placebo products. Prior to IC analysis, microwave-assisted acid hydrolysis was used to digest and release bound choline from powder and ready-to-feed (RTF) infant formula and adult nutritional samples. Following hydrolysis, separation of choline from common cations was achieved on a Thermo ScientificTM DionexTM IonPacTM CS19 column followed by suppressed conductivity detection. Total choline was measured and reported as the choline ion in mg/100 g reconstituted material or RTF as-is. The system was calibrated over the analytical range specified in the SMPR (2–250 mg/100 g). Recoveries of spiked samples at 50 and 100% of the fortified choline amounts ranged from 93.1 to 100.7% with RSDs ≤6.7% for product containing <2 mg/100 g and ≤4.1% for product containing 2–100 mg/100 g. Accuracy for the National Institute of Standards and Technology Standard Reference Material 1849a was determined over a 6-day interval and found to be 10.2 ± 0.2 mg/100 g calculated as the reconstituted powder with an RSD of 1.8%. The LOD was determined to be 0.009, and the LOQ 0.012 mg/100 g, well below the SMPR requirements of 0.7 and 2 mg/100 g, respectively. Repeatability RSDs over the range of the assay (2–200 mg/100 g) ranged from 1.0 to 5.93%


2015 ◽  
Vol 98 (6) ◽  
pp. 1655-1665 ◽  
Author(s):  
Linda D Butler-Thompson ◽  
Wesley A Jacobs ◽  
Karen J Schimpf ◽  
J Austad ◽  
B Chen ◽  
...  

Abstract AOAC First Action Method 2011.10, Vitamin B12 in Infant and Pediatric Formulas and Adult Nutritionals, was collaboratively studied. This method uses a pH 4.5 sodium acetate buffer and potassium cyanide at 105°C to extract and convert all biologically active forms of vitamin B12 present to cyanocobalamin; octylsilyl (C8) or C18 SPE cartridges to purify and concentrate cyanocobalamin; a combination of size-exclusion and RPLC to isolate cyanocobalamin; and visible absorbance at 550 nm to detect and quantitate cyanocobalamin in infant, pediatric, and adult nutritionals with vitamin B12 concentrations greater than 0.025 μg/100 g ready-to-feed (RTF) liquid. During this collaborative study, nine to 11 laboratories from eight different countries analyzed blind duplicates of 12 infant, pediatric, and adult nutritional formulas. Per the AOAC Expert Review Panel (ERP) on Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Nutrient Methods the method demonstrated acceptable repeatability and reproducibility and met SPIFAN Standard Method Performance Requirements (SMPRs®) for the majority of product matrixes analyzed. Vitamin B12 SPIFAN SMPRs for repeatability were ≤15% RSD at vitamin B12 concentrations of 0.01 μg/100 g RTF liquid and ≤7% RSD at vitamin B12 concentrations of 0.2–5.0 μg/100 g RTF liquid. Vitamin B12 SPIFAN SMPRs for reproducibility were ≤11% RSD in products with vitamin B12 concentrations ranging from 0.3 to 5.0 μg/100 g RTF liquid. During this collaborative study, the RSDr ranged from 2.98 to 9.77%, and the RSDR ranged from 3.54 to 19.5%. During previous single-laboratory validation studies, the method LOQ was estimated to be 0.025 μg/100 g RTF liquid.


2020 ◽  
Vol 103 (2) ◽  
pp. 489-493 ◽  
Author(s):  
Elizabeth M Mudge ◽  
Paula N Brown

Abstract Background Legalization of Cannabis across many U.S. states and in Canada had led to an urgent need for validated analytical methods for the quantitation of cannabinoids in Cannabis sativa L. flowers and finished products. The AOAC Stakeholder Panel on Strategic Food Analytical Methods Cannabis Expert Review Panel (ERP) approved an HPLC-diode-array detection (DAD) method for First Action Official MethodsSM status. Objective To present Official Methods of AnalysisSM (OMA) 2018.10 method details, validation results, and additional method extension data as approved by the ERP and further requirements for Final Action Official MethodsSM status. Methods This previously published method used 80% aqueous methanol via sonication for extracting eight cannabinoids—tetrahydrocannabidiolic acid, tetrahydrocannabinol, cannabidiolic acid, cannabidiol, tetrahydrocannabivarin, cannabigerol, cannabinol, and cannabichromene—in dried flowers followed by reversed-phase chromatographic separation and UV detection. Results The original method underwent extensive method optimization and a single-laboratory validation. Additional requirements requested by the Standard Method Performance Requirement (SMPR®) included a method extension, which was performed to collect repeatability data on two additional cannabinoids: cannabidivarinic acid and cannabigerolic acid. The methods performance was compared with the AOAC SMPR 2017.002 and 2017.001. RSDr ranged from 0.78 to 10.08% and recoveries from 90.7 to 99.2% in several different chemotypes. Conclusions The ERP adopted the method and provided recommendations for achieving Final Action status. Highlights After submission of additional validation data, an HPLC-DAD method for quantitation of cannabinoids in dried flowers and oils was accepted for First Action Official Method status (OMA 2018.10).


2013 ◽  
Vol 96 (4) ◽  
pp. 802-807 ◽  
Author(s):  
Karen Schimpf ◽  
Linda Thompson ◽  
Steve Baugh

Abstract This method for the determination of vitamin C by HPLC allows for the separation and quantitation of L-ascorbic acid in infant, pediatric, and adult nutritional products. Liquids, semisolids, and powders ranging from 2 to 1000 mg/kg in their consumable forms were analyzed during the method validation. The method met the standard method performance requirements and was approved by an AOAC Expert Review Panel on Infant Formula and Adult Nutritionals on October 2, 2012. During validation, the overall intermediate precision was 2.1% RSD (triplicate determinations on 7–10 days); the within-day precision, or repeatability, was 1.54% RSD (triplicate determinations). Accuracy, as spike recovery, ranged from 97.0 to 100.9%. The method detection and quantitation limits were determined experimentally to be 0.02 and 0.06 mg/L, respectively, in prepared samples.


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