Results 231 to 240 of about 2,787,968 (277)

Development of a Stable Isotope Dilution Assay for Tenuazonic Acid

Journal of Agricultural and Food Chemistry, 2011
A stable isotope dilution assay (SIDA) for the Alternaria mycotoxin tenuazonic acid was developed. Therefore, [(13)C(6),(15)N]-tenuazonic acid was synthesized from [(13)C(6),(15)N]-isoleucine by Dieckmann intramolecular cyclization after acetoacetylation with diketene.
Stefan Asam, Michael Rychlik
exaly   +4 more sources

Rapid degradation of the mycotoxin patulin in man quantified by stable isotope dilution assays

Food Additives and Contaminants, 2003
The absorption and degradation of the mycotoxin patulin in man was quantified by using a recently developed stable isotope dilution assay. Application of this currently most sensitive method revealed a patulin content less than 200 ng l(-1) in the blood serum of five consumers of apple juice.
Michael Rychlik
exaly   +3 more sources

Convenient Synthesis of Stable Deuterium-Labeled Alkylpyrazines for Use in Stable Isotope Dilution Assays

Journal of Agricultural and Food Chemistry, 2013
Stable isotope dilution assays (SIDA) provide for accurate and precise quantitation of aroma components, such as alkylpyrazines, which are often present in low concentrations in complex food matrices. The unavailability of labeled standards is the main limitation to the widespread use of SIDA.
Keith R Cadwallader
exaly   +3 more sources

Determination of potent odourants in roasted coffee by stable isotope dilution assays

Flavour and Fragrance Journal, 1995
AbstractStable isotope dilution assays were developed for 14 important odourants of roasted coffee. The following amounts (mg/kg) were found in the Arabica (I) and the Robusta (II) coffees: 2‐furfurylthiol (1.08 I, 1.73 II), methional (0.24 I, 0.095 II), 3‐mercapto‐3‐methylbutyl formate (0.13 I, 0.115 II), 2‐ethyl‐3‐5‐dimethylpyrazine (0.33 I, 0.94 II),
W Grosch
exaly   +2 more sources

Stable Isotope Dilution Assays of Alternariol and Alternariol Monomethyl Ether in Beverages

Journal of Agricultural and Food Chemistry, 2009
Stable isotope dilution assays (SIDAs) for the determination of the most important mycotoxins of the black mold Alternaria, namely, alternariol and alternariol monomethyl ether, have been developed. For this purpose, deuterated alternariol and alternariol methyl ether were synthesized by palladium catalyzed protium-deuterium exchange from the unlabeled
Stefan Asam, Michael Rychlik, Peter Schieberle   +2 more
exaly   +3 more sources

Revised folate content of foods determined by stable isotope dilution assays

Journal of Food Composition and Analysis, 2004
Abstract Stable isotope dilution assays were applied to quantify folates in several vegetables, orange juice, meat, liver, bread, and rice. The results were compared to data in the literature and in food data bases revealing significantly lower folate contents in broccoli and bread.
Michael Rychlik
exaly   +2 more sources

Quantitation of folates and their catabolites in blood plasma, erythrocytes, and urine by stable isotope dilution assays

Analytical Biochemistry, 2010
New stable isotope dilution assays were developed for the simultaneous quantitation of the folates 5-methyltetrahydrofolic acid, 5-formyltetrahydrofolic acid, tetrahydrofolic acid, 10-formylfolic acid, and folic acid as well as for their catabolites para-aminobenzoylglutamate (pABG) and acetyl-para-aminobenzoylglutamate (ApABG) in clinical samples. The
Michael Netzel, Michael Rychlik, Gabriele Netzel   +2 more
exaly   +6 more sources

Quantification of the Mycotoxin Patulin by a Stable Isotope Dilution Assay

Journal of Agricultural and Food Chemistry, 1999
Two stable isotope dilution assays for the quantification of patulin [4-hydroxy-4H-furo[3,2-c]pyran-2(6H)-one] in foods were developed using (13)C-labeled patulin as the internal standard. One method was performed by means of LC/MS in negative electrospray ionization mode without derivatization; the other used HRGC/HRMS after trimethylsilylation of the
M, Rychlik, P, Schieberle
openaire   +2 more sources

Development of Stable Isotope Dilution Assays for the Analysis of Natural Forms of Vitamin B12 in Meat

Journal of Agricultural and Food Chemistry, 2021
The first multiple stable isotope dilution assay method was developed for the simultaneous determination of four cobalamins, namely, hydroxocobalamin (OHCbl), adenosylcobalamin (AdoCbl), methylcobalamin (MeCbl), and cyanocobalamin (CNCbl), in their native forms. The sample preparation was optimized with enzyme treatment and immunoaffinity purification.
Mengle Wang, Stefan Asam, Jianqi Chen, Michael Rychlik   +3 more
openaire   +4 more sources

Quantification of the mycotoxins patulin and ochratoxin A by stable isotope dilution assays

Mycotoxin Research, 2005
For analysis of trace compounds, stable isotope dilution assays (SIDAs) have gained increasing importance in the past years. This methodology is based on the use of stable isotopically labelled analogues of the analytes as internal standards (IS). To take the mycotoxins patulin and ochratoxin A as examples, the benefits of SIDAs were demonstrated both ...
M, Rychlik, F, Lippl, M, Lindenmeier, F, Kircher, V, Schusdziarra, P, Schieberle   +5 more
openaire   +2 more sources