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Inoue K.,Kinjo Gakuin University | Dowell D.,AOAC INTERNATIONAL
Journal of AOAC International | Year: 2012

Official MethodSM 2011.21 is for the quantitation of the following nucleotides: adenosine 5'-monophosphate (AMP), guanosine 5'-monophosphate (GMP), uridine 5'-monophosphate (UMP), cytidine 5'-monophosphate (CMP), and inosine 5'-monophosphate (IMP) in infant formula and adult/pediatric nutritional formula. It uses hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS). Preparation of the internal standards was conducted using centrifugal ultrafiltration and the standards are AMP-13C 10, 15N5; GMP-13C10, 15N5; UMP-13C9, 15N 2; and CMP-13C9, 15N3. Data were collected by using multiple reaction monitoring of the product ions of protonated molecules of the five nucleotides generated by positive-electrospray ionization. The HILIC conditions were conducted with ammonium formate (30 mmol/L) in water (pH 2.5, adjusted with formic acid) and methanol. The LOD and LOQ of the standard solution were 0.005-0.01 and 0.01-0.03 μg/mL, respectively. Recovery data were collected for intraday and interday testing and ranged from 98.1 to 108.9% with an RSD of 0.7-5.4%. The analytical range of the method is between 0.04 to 5 μg/mL for standard solution. © 2012 Publishing Technology. Source

Pacquette L.H.,Abbott Laboratories | Levenson A.M.,Abbott Laboratories | Thompson J.J.,Abbott Laboratories | Dowell D.,AOAC INTERNATIONAL
Journal of AOAC International | Year: 2013

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%. Source

Vyas P.,Asure Quality Auckland Laboratory | O'Kane A.A.,Queens University of Belfast | Dowell D.,AOAC INTERNATIONAL
Journal of AOAC International | Year: 2012

At the "Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting" on June 29, 2011, an Expert Review Panel (ERP) agreed to further examine AOAC Official MethodSM 2011.01, "Determination of Vitamin B12 by Surface Plasmon Resonance," for use with infant formula and adult nutritionals. The original collaborative study was conducted using the Biacore Q TMbiosensor instrument and the Biacore QTM Qflex TM Kit Vitamin B12 Pl. Samples included in the study were infant formula, cereals, premixes, vitamin tablets, dietary supplements, and baby food. Eleven laboratories participated in the collaborative study. The results demonstrated a repeatability RSD (RSDr) of 1.59-27.8 and HorRat values for reproducibility of 0.34-1.89 in samples with levels ranging from ppm to ppb. The assay studied is a label-free protein binding-based assay that uses the principle of surface plasmon resonance to measure the interaction between vitamin B12 and a specific binding protein by passing a portion of the prepared sample extract combined with binding protein solution across a functionalized sensor chip. The response from the functionalized sensor chip is given as free-binding protein, as the mixture binds to the prepared surface of the chip. The ready-to-use Qflex Kit Vitamin B12 PI provides the reagents and accessories necessary to perform this assay. AOAC Method 2011.01 was approved by the AOAC Method Committee on Food Nutrition for Official First Action status, applicable to a wide range of food products, dietary supplements, and multivitamin premixes. After evaluation of the validation data available, an ERP agreed in June 2011 that the method meets standard method performance requirements, as articulated by the Stakeholder Panel on Infant Formula and Adult Nutritionals. The ERP granted the method First Action status, applicable to infant formula and adult/pediatric nutritional formula. © 2012 Publishing Technology. Source

Schimpf K.,Abbott Laboratories | Thompson L.,Abbott Laboratories | Baugh S.,AOAC INTERNATIONAL
Journal of AOAC International | Year: 2012

Myo-inositol is a 6-carbon cyclic polyalcohol also known as meso-inositol, meat sugar, inosite, and i-inositol. It occurs in nature in both free (myo-inositol) and bound (inositol phosphates and phosphatidylinositol) forms. For the determination of free myo-inositol, samples are mixed with dilute hydrochloric acid to extract myo-inositol and precipitate proteins, diluted with water, and filtered. For the determination of myo-inositol bound as phosphatidylinositol, samples are extracted with chloroform, isolated from other fats with silica SPE cartridges, and hydrolyzed with concentrated acid to free myo-inositol. Prepared samples are first injected onto a Dionex CarboPac PA1 column, which separates myo-inositol from other late-eluting carbohydrates. After column switching, myo-inositol is further separated on a CarboPac MA1 column using a 0.12% sodium hydroxide mobile phase; strongly retained carbohydrates are eluted from the PA1 column with a 3% sodium hydroxide mobile phase. Eluant from the CarboPac MA1 analytical column passes through an electrochemical detector cell where myo-inositol is detected by pulsed amperometry using a gold electrode. The method showed appropriate performance characteristics versus selected established standard method performance requirement parameters for the determination of myo-inositol: linear response; repeatability (RSDr) of 2%; and intermediate precision (RSDir) of 2.5%. Instrument LOD and LOQ were 0.0004 and 0.0013 mg/100 mL, respectively, and correspond to a free myo-inositol quantitation limit of 0.026 mg/100 g and a phosphatidylinositol quantitation limit of 0.016 mg/100 g. Correlation with the reference microbiological assay was good. The proposed method has been accepted by the Expert Review Panel as an AOAC First Action Method, suitable for the routine determination of myo-inositol in infant formula and adult nutritionals. Source

Accreditation and Quality Assurance | Year: 2011

AOAC INTERNATIONAL has developed a process to set Standard Method Performance Requirements (SMPRs). The fitness for intended use of the result of the measurement determines the criteria for these requirements. These criteria are specified by the stakeholder panels made up of key experts from global government, industry, academia, and contract research organizations. This process has been implemented for assays aiming at the detection of bio-threat agents, endocrine disruptors, and quantifying nutrients in infant formula. The process begins with the formation of a balanced stakeholder panel. The stakeholder panel specifies analytes, matrices, current technologies, analytical challenges, and regulatory information at the first meeting. Working groups are formed to provide specific technical expertise to the stakeholder panels. These groups perform the task of translating the specified needs of the stakeholder panel into concise measurement requirements. The draft SMPRs go back to the stakeholder panel for review and approval and then are posted for comment on the AOAC web site. These requirements become consensus requirements that have been developed with openness, balance of interests, an appeals procedure, consensus, and transparency. © 2011 Springer-Verlag. Source

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