Erik Konings - Academia.edu (original) (raw)
Papers by Erik Konings
Journal of AOAC International
A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in i... more A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in infant formula. Total vitamin B6 was quantified by converting the phosphorylated and free vitamers into pyridoxine. Pyridoxine was determined by ion pair reversed-phase LC with fluorescence detection. The method was subjected to an AOAC collaborative study involving a factory-manufactured, milk- and soy-based infant formula. Each was spiked at 3 concentrations in the range of 0-1 microg/g and sent as blind duplicate to participant laboratories. Nine laboratories returned valid data which were statistically analyzed for outliers and precision parameters. The repeatability relative standard deviation (RSD(r)) ranges were 2.0-4.0 and 3.5-5.9% for fortified milk- and soy-based formulas, respectively. The reproducibility relative standard deviation (RSD(R)) ranges were 8.2-8.4 and 6.7-11.2% for fortified milk- and soy-based formulas, respectively. HORRAT values ranged from 0.42 to 0.53, indica...
Journal of AOAC International
Simultaneous Determination of Vitamins.-Klejdus et al. (1) described a simultaneous determination... more Simultaneous Determination of Vitamins.-Klejdus et al. (1) described a simultaneous determination of 10 waterand 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. (2) described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were <6.5%. The concentrations of vitamins found in premixes with the method were comparable to the values declared. A disadvantage of the methods mentioned above is that sample composition has to be known in advance. According to European legislation, for example, foods might be fortified with riboflavin phosphate or thiamin phosphate, vitamers which are not included in the simultaneous separations described. Vitamin B 2 .-Viñas et al. (3) elaborated an LC analysis of riboflavin vitamers in foods. Vitamin B 2 can be found in nature as the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). Several methods usually involve the conversion of these coenzymes into free riboflavin before quantification of total riboflavin. According to the authors, there is growing interest to know flavin composition of foods. The described method separates the individual vitamers isocratically. Accuracy of the method is tested with 2 certified reference materials (CRMs). Vitamin B 5 .-Methods for the determination of vitamin B 5 in foods are limited because of their low sensitivity and poor selectivity. Pakin et al. (4) proposed a post-column derivatization of pantothenic acid as a fluorescent compound and used this principle in a specific and sensitive method for the determination of free and bound pantothenic acid in a large variety of foods. A French laboratory invited European Year of interlaboratory test
Determination of total fluoroacetic acid and its salts in all forms of infant formula is evaluate... more Determination of total fluoroacetic acid and its salts in all forms of infant formula is evaluated. Infant formula includes breast-milk substitute specially manufactured to satisfy, by itself, the nutritional requirements of infants during the first months of life up to the introduction of appropriate complementary feeding, made from any combination of milk, soy, rice, whey, hydrolyzed protein, starch, and amino acids, with and without intact protein. Suitable methods will include blank check samples, and check standards at the lowest point and midrange point of the analytical range.
Food Control
Abstract Infant formulas are strictly regulated and rigorously tested for compliance. Recently, n... more Abstract Infant formulas are strictly regulated and rigorously tested for compliance. Recently, new official analytical methods/standards have been established for nutrient analyses in these product categories through the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), governed by AOAC INTERNATIONAL. Many of these methods have been adopted or are in the process of being adopted as reference methods by Codex Alimentarius. The purpose of this paper is to assess the ability of these cutting-edge analytical methods to deliver acceptable results in the context of established regulatory limits for nutrients in food standards and regulations. For this evaluation, the analytical method variability is considered as one of the three main sources of overall process variability, which also includes variation in raw materials/ingredients and the manufacturing process. The process capability (Cp) is a concept for determining the overall process variability relative to specification limits for a parameter in the final product. Based on this principle an analytical method capability (Cm) was defined and calculated for SPIFAN methods. Global regulatory requirements were evaluated including minimum and maximum limits and tolerances from the declared label values. Compared to these requirements, analytical methods for vitamins A, B12, D and folic acid are of particular concern in relation to the requirements in China, some EU member states, Pakistan, Russia, Singapore, South Africa and Thailand. For a product with a manufacturing target at the midpoint of the regulatory range for these nutrients, the probability of obtaining an analytical result outside the regulatory requirements due to analytical variation alone can be as high as 19%. This does not consider variability caused by the production process and/or raw materials/ingredients. These currently used analytical methods are state-of-the-art and represent the latest developments in technology. However, this work demonstrates that continuous method improvements for the nutrients identified must be pursued. In addition, this work supports a risk management approach that takes into consideration analytical method capability when establishing regulatory limits for nutrients in infant formulas. Ongoing efforts towards harmonization of regulatory requirements across global markets will facilitate evaluation of regulatory compliance in infant formulas.
Journal of AOAC INTERNATIONAL
is that it can provide accurate mass values, and the exact number of monosaccharides present in a... more is that it can provide accurate mass values, and the exact number of monosaccharides present in an oligosaccharide can be found. Conversely, a disadvantage of MALDI-TOF MS is that it is a destructive technique and, therefore, preparative work cannot be undertaken. Fluorophore-assisted carbohydrate electrophoresis (FACE) technology is also used to separate and detect oligosaccharides, particularly from glycoconjugates. Analysis involves 4 steps: release, labeling with a fluorescent tag, separation using precast polyacrylamide gels, and imaging. Although FACE technology is simple and reliable, its use is not yet widespread. This may be due to a lack of papers describing specific applications, or possibly due to unfamiliarity with the technique. Another technique also used to separate and detect oligosaccharides is the automated use of modern planar chromatography. This utilizes HPTLC plates, automated multiple development, completely automated elution systems, and sample positioning and spots detection apparatus, all of which allows reproducible separation of different oligosaccharides and other compounds in complex mixtures. Despite the improvement of TLC and HPLC techniques, gas chromatography (GC) still continues to have a place in oligosaccharide analysis, particularly for structural studies, although prederivatization is required. Nuclear magnetic resonance (NMR) is a powerful technique used to elucidate the structure of oligosaccharides, especially with the advent of 2-D and various hyphenated methods for the determination of position and configuration of glycosidic linkages. Many of the separation and analytical techniques mentioned above are used in conjunction with enzymatic or chemical degradation of an unknown oligosaccharide. A typical structural analysis of a complex oligosaccharide may involve partial acid hydrolysis or hydrolysis by specific enzymes, followed by separation and identification of the hydrolytic products. This combination of methods often yields structural information that cannot be obtained by methylation analysis, NMR, or chromatographic techniques alone. In particular, monomer sequence and distribution of branches and other substituents may be obtained in this way.
The American Journal of Clinical Nutrition
EDITOR tion systems, such as electrochemical or mass spectrometry, have been developed (6). There... more EDITOR tion systems, such as electrochemical or mass spectrometry, have been developed (6). There is also the possibility that the bacteria used in the MA gave unequal responses to the different vitamers or can be affected by some nonfolate compounds in the samples. However, the latter was evaluated on the basis of the combined LC-MA results. The data clearly show the absence of any nonfolate peaks with organism activity. We conclude that the MA is preferred for the determination of the total folate content of foods, especially if data on individual folates is not considered necessary. Furthermore, we stress the need for careful validation of HPLC methods. Given the considerable, yet unidentified, difference between the microbiological and HPLC data, we advise caution when estimating dietary folate intakes at the population level.
Journal of AOAC International
Background: Monochloropropanediol (MCPD) and its fatty acid esters as well as glycidyl fatty acid... more Background: Monochloropropanediol (MCPD) and its fatty acid esters as well as glycidyl fatty acid esters are substances generated during oil refining or food processing. The free form released during digestion, 3-MCPD and glycidol, have shown adverse effects in animal studies. Objective: So far, the available analytical methods have not been validated in a collaborative study for infant and adult nutritional formulas. This manuscript describes a single-laboratory validation method in view of a future multilaboratory validation trial. Methods: The method described is for the direct determination of 2- and 3-MCPD and indirect determination of 2- and 3-MCPD esters and glycidyl esters in infant and adult/pediatric nutritional formulas by GC coupled to MS. Results: The analytical range was found to be 4–2000 μg/kg powder formula and 0.7–333 μg/kg liquid formula for fatty acid esters of MCPD and glycidol, and 2.5–750 μg/kg samples for free MCPD. The recovery rates were within 91–124% for ...
Journal of AOAC International, Jul 1, 2017
AOAC SMPRs describe the minimum recommended performance characteristics to be used during the eva... more AOAC SMPRs describe the minimum recommended performance characteristics to be used during the evaluation of a method. The evaluation may be an on-site verification, a singlelaboratory validation, or a multi-site collaborative study. SMPRs are written and adopted by AOAC stakeholder panels composed of representatives from the industry, regulatory organizations, contract laboratories, test kit manufacturers, and academic institutions. AOAC SMPRs are used by AOAC expert review panels in their evaluation of validation study data for methods being considered for Performance Tested MethodsSM or AOAC Official Methods of AnalysisSM, and can be used as acceptance criteria for verification at user laboratories.
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, 2016
A brief overview of the main analytical approaches and practices to determine food authenticity i... more A brief overview of the main analytical approaches and practices to determine food authenticity is presented, addressing, as well, food supply chain and future requirements to more effectively mitigate food fraud. Food companies are introducing procedures and mechanisms that allow them to identify vulnerabilities in their food supply chain under the umbrella of a food fraud prevention management system. A key step and first line of defense is thorough supply chain mapping and full transparency, assessing the likelihood of fraudsters to penetrate the chain at any point. More vulnerable chains, such as those where ingredients and/or raw materials are purchased through traders or auctions, may require a higher degree of sampling, testing, and surveillance. Access to analytical tools is therefore pivotal, requiring continuous development and possibly sophistication in identifying chemical markers, data acquisition, and modeling. Significant progress in portable technologies is evident a...
Journal of AOAC International
Water-soluble vitamins (WSVs) are a group of organic compounds which are essential micronutrients... more Water-soluble vitamins (WSVs) are a group of organic compounds which are essential micronutrients. WSVs could be divided between the B complex group and vitamin C (l-ascorbic acid). Within the B complex group, eight vitamins are recognized: vitamins B1 (thiamin), B2 (riboflavin), B3 (niacin or niacinamide), B5 (pantothenic acid), B6 (pyridoxine, pyridoxal, or pyridoxamine), B7 (biotin), B9 (folic acid), and B12 (various cobalamins). This paper reviews the new methods for the analysis of these vitamins, with a focus on infant formula and adult nutritionals.
Journal of AOAC International, 2016
Journal of AOAC International, 2016
Journal of AOAC International, 2015
Determination of monofluoroacetate in powdered nutritional products by derivatization with 2-nitr... more Determination of monofluoroacetate in powdered nutritional products by derivatization with 2-nitrophenylhydrazine and LC-MS/MS IS discussed. Samples are prepared by dilution in water followed by protein precipitation with acetonitrile. An aliquot of the sample extract is derivatized with 2-nitrophenylhydrazine (2-NPH) in the presence of 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). This reaction achieves the coupling of the carboxyl group of monofluoroacetate to the amino group of 2-NPH with the formation of an amide bond. Samples are processed through a solid-phase extraction (SPE) step in order to exchange.
Acrylamide and Other Hazardous Compounds in Heat-Treated Foods, 2006
Journal of AOAC International
Methods under consideration as part of the AOAC Stakeholder Panel on Infant Formula and Adult Nut... more Methods under consideration as part of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals process are to be evaluated against a set of Standard Method Performance Requirements(SM) (SMPRs) via peer review by an expert review panel (ERP). A validation protocol and a checklist have been developed to assist the ERP to evaluate experimental data and to compare multiple candidate methods for each nutrient. Method performance against validation parameters mandated in the SMPRs as well as additional criteria are to be scored, with the method selected by the ERP proceeding to multilaboratory study prior to Final Action approval. These methods are intended to be used by the infant formula industry for the purposes of dispute resolution.
Journal of AOAC International
A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in i... more A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in infant formula. Total vitamin B6 was quantified by converting the phosphorylated and free vitamers into pyridoxine. Pyridoxine was determined by ion pair reversed-phase LC with fluorescence detection. The method was subjected to an AOAC collaborative study involving a factory-manufactured, milk- and soy-based infant formula. Each was spiked at 3 concentrations in the range of 0-1 microg/g and sent as blind duplicate to participant laboratories. Nine laboratories returned valid data which were statistically analyzed for outliers and precision parameters. The repeatability relative standard deviation (RSD(r)) ranges were 2.0-4.0 and 3.5-5.9% for fortified milk- and soy-based formulas, respectively. The reproducibility relative standard deviation (RSD(R)) ranges were 8.2-8.4 and 6.7-11.2% for fortified milk- and soy-based formulas, respectively. HORRAT values ranged from 0.42 to 0.53, indica...
Journal of AOAC International
Simultaneous Determination of Vitamins.-Klejdus et al. (1) described a simultaneous determination... more Simultaneous Determination of Vitamins.-Klejdus et al. (1) described a simultaneous determination of 10 waterand 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. (2) described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were <6.5%. The concentrations of vitamins found in premixes with the method were comparable to the values declared. A disadvantage of the methods mentioned above is that sample composition has to be known in advance. According to European legislation, for example, foods might be fortified with riboflavin phosphate or thiamin phosphate, vitamers which are not included in the simultaneous separations described. Vitamin B 2 .-Viñas et al. (3) elaborated an LC analysis of riboflavin vitamers in foods. Vitamin B 2 can be found in nature as the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). Several methods usually involve the conversion of these coenzymes into free riboflavin before quantification of total riboflavin. According to the authors, there is growing interest to know flavin composition of foods. The described method separates the individual vitamers isocratically. Accuracy of the method is tested with 2 certified reference materials (CRMs). Vitamin B 5 .-Methods for the determination of vitamin B 5 in foods are limited because of their low sensitivity and poor selectivity. Pakin et al. (4) proposed a post-column derivatization of pantothenic acid as a fluorescent compound and used this principle in a specific and sensitive method for the determination of free and bound pantothenic acid in a large variety of foods. A French laboratory invited European Year of interlaboratory test
Determination of total fluoroacetic acid and its salts in all forms of infant formula is evaluate... more Determination of total fluoroacetic acid and its salts in all forms of infant formula is evaluated. Infant formula includes breast-milk substitute specially manufactured to satisfy, by itself, the nutritional requirements of infants during the first months of life up to the introduction of appropriate complementary feeding, made from any combination of milk, soy, rice, whey, hydrolyzed protein, starch, and amino acids, with and without intact protein. Suitable methods will include blank check samples, and check standards at the lowest point and midrange point of the analytical range.
Food Control
Abstract Infant formulas are strictly regulated and rigorously tested for compliance. Recently, n... more Abstract Infant formulas are strictly regulated and rigorously tested for compliance. Recently, new official analytical methods/standards have been established for nutrient analyses in these product categories through the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), governed by AOAC INTERNATIONAL. Many of these methods have been adopted or are in the process of being adopted as reference methods by Codex Alimentarius. The purpose of this paper is to assess the ability of these cutting-edge analytical methods to deliver acceptable results in the context of established regulatory limits for nutrients in food standards and regulations. For this evaluation, the analytical method variability is considered as one of the three main sources of overall process variability, which also includes variation in raw materials/ingredients and the manufacturing process. The process capability (Cp) is a concept for determining the overall process variability relative to specification limits for a parameter in the final product. Based on this principle an analytical method capability (Cm) was defined and calculated for SPIFAN methods. Global regulatory requirements were evaluated including minimum and maximum limits and tolerances from the declared label values. Compared to these requirements, analytical methods for vitamins A, B12, D and folic acid are of particular concern in relation to the requirements in China, some EU member states, Pakistan, Russia, Singapore, South Africa and Thailand. For a product with a manufacturing target at the midpoint of the regulatory range for these nutrients, the probability of obtaining an analytical result outside the regulatory requirements due to analytical variation alone can be as high as 19%. This does not consider variability caused by the production process and/or raw materials/ingredients. These currently used analytical methods are state-of-the-art and represent the latest developments in technology. However, this work demonstrates that continuous method improvements for the nutrients identified must be pursued. In addition, this work supports a risk management approach that takes into consideration analytical method capability when establishing regulatory limits for nutrients in infant formulas. Ongoing efforts towards harmonization of regulatory requirements across global markets will facilitate evaluation of regulatory compliance in infant formulas.
Journal of AOAC INTERNATIONAL
is that it can provide accurate mass values, and the exact number of monosaccharides present in a... more is that it can provide accurate mass values, and the exact number of monosaccharides present in an oligosaccharide can be found. Conversely, a disadvantage of MALDI-TOF MS is that it is a destructive technique and, therefore, preparative work cannot be undertaken. Fluorophore-assisted carbohydrate electrophoresis (FACE) technology is also used to separate and detect oligosaccharides, particularly from glycoconjugates. Analysis involves 4 steps: release, labeling with a fluorescent tag, separation using precast polyacrylamide gels, and imaging. Although FACE technology is simple and reliable, its use is not yet widespread. This may be due to a lack of papers describing specific applications, or possibly due to unfamiliarity with the technique. Another technique also used to separate and detect oligosaccharides is the automated use of modern planar chromatography. This utilizes HPTLC plates, automated multiple development, completely automated elution systems, and sample positioning and spots detection apparatus, all of which allows reproducible separation of different oligosaccharides and other compounds in complex mixtures. Despite the improvement of TLC and HPLC techniques, gas chromatography (GC) still continues to have a place in oligosaccharide analysis, particularly for structural studies, although prederivatization is required. Nuclear magnetic resonance (NMR) is a powerful technique used to elucidate the structure of oligosaccharides, especially with the advent of 2-D and various hyphenated methods for the determination of position and configuration of glycosidic linkages. Many of the separation and analytical techniques mentioned above are used in conjunction with enzymatic or chemical degradation of an unknown oligosaccharide. A typical structural analysis of a complex oligosaccharide may involve partial acid hydrolysis or hydrolysis by specific enzymes, followed by separation and identification of the hydrolytic products. This combination of methods often yields structural information that cannot be obtained by methylation analysis, NMR, or chromatographic techniques alone. In particular, monomer sequence and distribution of branches and other substituents may be obtained in this way.
The American Journal of Clinical Nutrition
EDITOR tion systems, such as electrochemical or mass spectrometry, have been developed (6). There... more EDITOR tion systems, such as electrochemical or mass spectrometry, have been developed (6). There is also the possibility that the bacteria used in the MA gave unequal responses to the different vitamers or can be affected by some nonfolate compounds in the samples. However, the latter was evaluated on the basis of the combined LC-MA results. The data clearly show the absence of any nonfolate peaks with organism activity. We conclude that the MA is preferred for the determination of the total folate content of foods, especially if data on individual folates is not considered necessary. Furthermore, we stress the need for careful validation of HPLC methods. Given the considerable, yet unidentified, difference between the microbiological and HPLC data, we advise caution when estimating dietary folate intakes at the population level.
Journal of AOAC International
Background: Monochloropropanediol (MCPD) and its fatty acid esters as well as glycidyl fatty acid... more Background: Monochloropropanediol (MCPD) and its fatty acid esters as well as glycidyl fatty acid esters are substances generated during oil refining or food processing. The free form released during digestion, 3-MCPD and glycidol, have shown adverse effects in animal studies. Objective: So far, the available analytical methods have not been validated in a collaborative study for infant and adult nutritional formulas. This manuscript describes a single-laboratory validation method in view of a future multilaboratory validation trial. Methods: The method described is for the direct determination of 2- and 3-MCPD and indirect determination of 2- and 3-MCPD esters and glycidyl esters in infant and adult/pediatric nutritional formulas by GC coupled to MS. Results: The analytical range was found to be 4–2000 μg/kg powder formula and 0.7–333 μg/kg liquid formula for fatty acid esters of MCPD and glycidol, and 2.5–750 μg/kg samples for free MCPD. The recovery rates were within 91–124% for ...
Journal of AOAC International, Jul 1, 2017
AOAC SMPRs describe the minimum recommended performance characteristics to be used during the eva... more AOAC SMPRs describe the minimum recommended performance characteristics to be used during the evaluation of a method. The evaluation may be an on-site verification, a singlelaboratory validation, or a multi-site collaborative study. SMPRs are written and adopted by AOAC stakeholder panels composed of representatives from the industry, regulatory organizations, contract laboratories, test kit manufacturers, and academic institutions. AOAC SMPRs are used by AOAC expert review panels in their evaluation of validation study data for methods being considered for Performance Tested MethodsSM or AOAC Official Methods of AnalysisSM, and can be used as acceptance criteria for verification at user laboratories.
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, Jul 1, 2017
Journal of AOAC International, 2016
A brief overview of the main analytical approaches and practices to determine food authenticity i... more A brief overview of the main analytical approaches and practices to determine food authenticity is presented, addressing, as well, food supply chain and future requirements to more effectively mitigate food fraud. Food companies are introducing procedures and mechanisms that allow them to identify vulnerabilities in their food supply chain under the umbrella of a food fraud prevention management system. A key step and first line of defense is thorough supply chain mapping and full transparency, assessing the likelihood of fraudsters to penetrate the chain at any point. More vulnerable chains, such as those where ingredients and/or raw materials are purchased through traders or auctions, may require a higher degree of sampling, testing, and surveillance. Access to analytical tools is therefore pivotal, requiring continuous development and possibly sophistication in identifying chemical markers, data acquisition, and modeling. Significant progress in portable technologies is evident a...
Journal of AOAC International
Water-soluble vitamins (WSVs) are a group of organic compounds which are essential micronutrients... more Water-soluble vitamins (WSVs) are a group of organic compounds which are essential micronutrients. WSVs could be divided between the B complex group and vitamin C (l-ascorbic acid). Within the B complex group, eight vitamins are recognized: vitamins B1 (thiamin), B2 (riboflavin), B3 (niacin or niacinamide), B5 (pantothenic acid), B6 (pyridoxine, pyridoxal, or pyridoxamine), B7 (biotin), B9 (folic acid), and B12 (various cobalamins). This paper reviews the new methods for the analysis of these vitamins, with a focus on infant formula and adult nutritionals.
Journal of AOAC International, 2016
Journal of AOAC International, 2016
Journal of AOAC International, 2015
Determination of monofluoroacetate in powdered nutritional products by derivatization with 2-nitr... more Determination of monofluoroacetate in powdered nutritional products by derivatization with 2-nitrophenylhydrazine and LC-MS/MS IS discussed. Samples are prepared by dilution in water followed by protein precipitation with acetonitrile. An aliquot of the sample extract is derivatized with 2-nitrophenylhydrazine (2-NPH) in the presence of 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). This reaction achieves the coupling of the carboxyl group of monofluoroacetate to the amino group of 2-NPH with the formation of an amide bond. Samples are processed through a solid-phase extraction (SPE) step in order to exchange.
Acrylamide and Other Hazardous Compounds in Heat-Treated Foods, 2006
Journal of AOAC International
Methods under consideration as part of the AOAC Stakeholder Panel on Infant Formula and Adult Nut... more Methods under consideration as part of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals process are to be evaluated against a set of Standard Method Performance Requirements(SM) (SMPRs) via peer review by an expert review panel (ERP). A validation protocol and a checklist have been developed to assist the ERP to evaluate experimental data and to compare multiple candidate methods for each nutrient. Method performance against validation parameters mandated in the SMPRs as well as additional criteria are to be scored, with the method selected by the ERP proceeding to multilaboratory study prior to Final Action approval. These methods are intended to be used by the infant formula industry for the purposes of dispute resolution.