Determination of Folate in Infant Formula and Adult/Pediatric Nutritional Formula by Optical Biosensor Assay: First Action 2011.05

2012 ◽  
Vol 95 (2) ◽  
pp. 298-300 ◽  
Author(s):  
Harvey Indyk Fonterra ◽  
Dawn Dowell

Abstract After a review of data from a single-laboratory validation (SLV) study published in the International Dairy Journal 21, 783–789 (2011), a method for folate in infant formula and adult/pediatric nutritional formula was submitted for consideration of adoption by AOAC as an automated assay that is rapid and simple. The method uses an optical biosensor assay to quantitate total folate content in milk and milk-based pediatric and adult nutritional products. The assay uses folate binding protein and a functionalized sensor surface. The SLV showed an instrumental LOD of 0.1 ng/mL (equivalent to 2.5 μg/100 g for a typical infant formula). The method detection limit was 6.5 μg/100 g with a repeatability of 3.48% and an intermediate reproducibility of 4.63% RSD.

1994 ◽  
Vol 77 (5) ◽  
pp. 1288-1292 ◽  
Author(s):  
Nancy J Miller-Ihli

Abstract A method was developed for the determination of lead in sugars and syrups. Samples are wet-ashed with a nitric acid–hydrogen peroxide procedure and analyzed by graphite furnace atomic absorption spectrometry. The method involves the use of magnesium nitrate as a matrix modifier, air ashing, platform atomization, and quantitation by peak area measurements with direct calibration against aqueous standards. The instrumental detection limit (based on 3.29σ) was 10 pg, or 0.5 μg/L for a 20 μL injection, corresponding to a method detection limit of 3.3 ng/g sugar. The characteristic mass was approximately 12 pg. This method was validated by analyzing sucrose and high-fructose corn syrup samples spiked with known quantities of lead. The average recovery was 101 ± 6%.


Author(s):  
George Joseph ◽  
Asha Varughese ◽  
Ann Daniel

Abstract Background A method has been developed and validated for selective, accurate and precise determination of total proteinogenic amino acids and taurine from Infant Formula and Adult/Pediatric Nutritional Formulas (powders, ready-to-feed liquids, and liquid concentrates). The method was reviewed by the AOAC INTERNATIONAL SPIFAN Expert Review Panel (ERP) during the 133rd AOAC Annual Meeting & Expo on September 7, 2019 in Denver, CO, USA and was recommended to First Action Official MethodsSM status. Objective The method involves protein hydrolysis to amino acids, a simple pre-column derivatisation of amino acids and separation of derivatised amino acids by UHPLC. The quantification of amino acids is performed by multi-point calibration using norvaline as the internal standard. The analytical method is capable of quantitative determination for 22 proteinogenic amino acids, but cannot be used to quantitate tryptophan, which is destroyed during the acid hydrolysis step. Asparagine is determined as aspartic acid and glutamine as glutamic acid. The cystine and cysteine are converted to S-2-carboxyethylthiocysteine (CYSx) and the derivative is separated from the other amino acids. Citrulline which is present in some matrices and it is separated from other amino acids is not included in the method performance evaluation in the single laboratory validation (SLV). Method The proposed method met all the performance requirement limits set in standard method performance requirements (SMPR) 2014.013 for total proteinogenic amino acids and taurine. The correlation coefficient of multi-point calibration was not less than 0.999 for any amino acids at any point in the SLV study confirming the validity of linear dynanic range (LDR) and linearity of the method. The individual amino acids in the chromatogram were identified by absolute retention time and relative retention time (RRT) with respect to the internal standard norvaline. There were no significant (S/N Ratio <10) interferences from the reagents or by-products of derivatisation and targeted matrices. The method demonstrated high selectivity. Result Accuracy of the method was validated using standard reference materials (NIST SRM 1869 and 1849a) and spike recovery studies. The amino acid results in the SRMs were within the ranges of Reference Mass Fraction Values. The accuracy of the method was corroboratively validated by spike recovery studies. The average spike recovery range between 93 to 107% ensure the accuracy of the method for amino acids and compliance to the AOAC SMPR 2014.013. Conclusions Precision data of the method demonstrate that it meets the stakeholder requirements as per the SMPR. The mean RSDr for all the amino acids for 17 matrices selected for the SLV were not more than 4%. The method is very sensitive and the LOQ can go down to approximately ten times lower than the SMPR requirements. The sensitivity of method is a direct reflection of its signal to noise ratio which ensures guaranteed method performance at the lower levels of amino acids in these matrices. Highlights Taurine (aminoethane sulfonic acid) unlike the other amino acids is a beta-sulfonic amino acid that is not used in protein synthesis but is found as a free amino acid in tissues. The acidic functional group (-COOH) in common amino acid is replaced with a sulfonic acid (-SO3H) group in Taurine. The method offers baseline separation of citrulline which is an alpha amino acid generally present in Infant Formula and Adult/Pediatric Nutritional products. The separation of citrulline eliminates the risk of interference of this compound with other amino acids. The method can also separate and quantitate hydroxyproline, an important component of collagen that is often used to quantitate collagen. The method is simple and does not include any proprietary chemicals or instruments and can be performed on any basic reverse phase UHPLC system with UV detection.


2019 ◽  
Vol 102 (4) ◽  
pp. 1205-1220 ◽  
Author(s):  
Jan Kuhlmann

Abstract Background: Fatty acid esters of glycidol, 2-Monochloropropanediol (MCPD), and 3-MCPD are heat-induced foodborne processing contaminants with possible adverse health effects. These compounds occur frequently in refined edible oils. Consequently, glycidyl esters and 2- and 3-MCPD esters might also be present in foods that contain refined edible oils. Objective: This manuscript describes the single-laboratory validation of an analytical method for the quantitative determination of glycidol, 2-MCPD, and 3-MCPD present as fatty acid esters or as free 2- or 3-MCPD in infant and adult/pediatric nutritional formula. Methods: Technically, the presented method is based on the combination of a Heat-Ultrasound Pressure-supported Solvent Extraction and a GC–MS determination of glycidol, 2-MCPD, and 3-MCPD. From a chemical perspective, the method includes an alkaline catalyzed transesterification, conversion of the unstable glycidol into monobromopropanediol, and the parallel derivatization of all analytes with phenylboronic acid. Results: Validation results showed that method linearity for all analytes in powdered and liquid infant formula ranged from 0.9981 to 0.9999 (n = 18). Repeatability relative standard deviation values for concentration levels between 1.3 μg/kg and 331 μg/kg were in the range of 1 to 12%. Relative recoveries were found to be between 93 and 107%. The analytes were quantifiable down to 5–10 μg/kg in powdered samples and 1–2 μg/kg in liquid samples. Conclusions: The reported results met actual AOAC Standard Method Performance Requirements. Highlights: In terms of consumer protection, the presented method is a novel approach for the sensitive and accurate determination of glycidol, 2-MCPD, and 3-MCPD in infant formula and related foodstuffs.


2011 ◽  
Vol 94 (4) ◽  
pp. 1217-1226 ◽  
Author(s):  
Pathik Vyas ◽  
Anthony A O'kane ◽  
E Ager ◽  
S Crooks ◽  
C Elliott ◽  
...  

Abstract A collaborative study was conducted on an inhibition-based protein-binding assay using the Biacore Q™ biosensor instrument and the Biacore Qflex™ Kit Vitamin B12 PI. The samples studied included infant formula, cereals, premixes, vitamin tablets, dietary supplements, and baby food. The collaborative study, which involved 11 laboratories, demonstrated that the assay showed an 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 (SPR) to measure the interaction between vitamin B12 and a specifc binding protein. A Biacore Q biosensor uses this principle to detect binding directly at the surface of a sensor chip with a hydrophilic gold-dextran surface. The instrument passes a mixture of prepared sample extract and binding protein solution across a covalently immobilized vitamin B12 chip surface, and the response is given as free-binding protein as the mixture binds to the immobilized surface. This technique uses the specifcity and robustness of the protein-ligand interaction to allow minimal sample preparation and a wide range of matrixes to be analyzed rapidly. The reagents and accessories needed to perform this assay are provided as the ready-to-use format “Qflex Kit Vitamin B12 PI.” The method is intended for routine use in the quantitative determination of vitamin B12 (as cyanocobalamin) in a wide range of food products, dietary vitamin supplements, and multivitamin premixes.


2008 ◽  
Vol 91 (4) ◽  
pp. 777-785 ◽  
Author(s):  
Pierre Andrieux ◽  
Tamara Kilinc ◽  
Christian Perrin ◽  
Esther Campos-Giménez

Abstract A single-laboratory validation study was conducted for a liquid chromatographic/mass spectrometric (LC/MS) method for the simultaneous determination of the free carnitine and total choline in milk-based infant formula and health-care products. The sample preparation used for both carnitine and choline was adapted from AOAC Official Method 999.14, with an acidic and enzymatic hydrolysis of esterified forms of choline. Carnitine and choline were quantified by ion-pair chromatography with single-quadrupole MS detection, using their respective deuterated internal standards. The repeatability relative standard deviation was 2.5 and 2.1, respectively, for carnitine and choline. The intermediate reproducibility relative standard deviation was <4.7 and 2.4, respectively, for carnitine and choline. The ranges of the average product-specific recoveries were 9298 and 94103, respectively, for carnitine and choline. Choline concentration determined in infant formula reference material SRM 1846 was in agreement with the reference value. The proposed method was compared with the enzymatic methods for a range of products; good correlation (r = 0.99) was obtained, although a significant bias was observed for both analytes. The method, with a short chromatographic run time (7 min), is convenient for routine analysis to enhance analytical throughput and is a good alternative to enzymatic assays.


2016 ◽  
Vol 99 (1) ◽  
pp. 242-251 ◽  
Author(s):  
Lauren M Fleury ◽  
Bryan G Scahill ◽  
Rilka Taskova

Abstract A single-laboratory validation (SLV) study was conducted for the determination of sodium fluoroacetate in dairy powders by LC-tandem MS (LC-MS/MS). Linearity of response was confirmed by analysis of samples fortified over the concentration range 0.10–100 μg/kg. The LOD was estimated to be 0.028 μg/kg (0.028 ppb) from the SD of the measured concentrations of infant formula samples fortified at 0.10 μg/kg. The corresponding LOQ calculates at 0.085 μg/kg (0.085 ppb), which ensures excellent reliability of quantification at the limit of reporting of 1.0 μg/kg (1 ppb). Repeatability and intermediate precision were estimated from the SD of the recovery of samples fortified at 0.075, 0.10, 0.20, 0.50, 1.0, and 10.0 μg/kg. The previously mentioned method performance values were established using a representative stage 2 (6–12 months) bovine infant formula, and the robustness of the method was tested by the analysis of 107 unique dairy powders and formulations fortified at 1.0 μg/kg. The data collected in this study satisfy the requirements of SLV studies established by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), and the method was awarded First Action Official MethodSM status by the AOAC Expert Review Panel on SPIFAN Nutrient Methods (Contaminants) on March 17, 2015.


2016 ◽  
Vol 99 (1) ◽  
pp. 204-209 ◽  
Author(s):  
David J Ellingson ◽  
Jeffrey J Shippar ◽  
Justin M Gilmore

Abstract Analytical methods for the analysis of both L-carnitine and choline are needed for reliable and accurate determination in infant formula and adult/pediatric nutritional formula. These compounds are different in how they are utilized by the human body, but are structurally similar. L-carnitine and choline are quaternary ammonium compounds, enabling both to be retained under acidic conditions with strong cation exchange (SCX) chromatography. This method analyzes both compounds simultaneously as either the free forms or as a total amount that includes bound sources such as phosphatidylcholine or acetylcarnitine. The free analysis consists of water extraction and analysis by LC/MS/MS, while the total analysis consists of extraction by acid assisted microwave hydrolysis and analysis by LC/MS/MS. Calibration standards used for calculations are extracted with all samples in the batch. A single laboratory validation (SLV) was performed following the guidelines of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) utilizing the kit of materials provided. The results achieved meet the requirements of SMPR 2012.010 and 2012.013 for L-carnitine and total choline, respectively.


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.


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