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3/17/2015

“DERIVATIZATION” ANALYSIS METHOD

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SAMPLE PREPARATION

• Samples are prepared by dilution in water followed by protein precipitation with acetonitrile. • An aliquot of the sample extract is derivatized with 2 nitro phenylhydrazide (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 step in order to exchange sample solvent and achieve a 5-fold concentration of the extract. • A stable-isotope labeled internal standard is incorporated into the sample preparation to correct for instrument response and losses in sample preparation. • Overall sample dilution of 1:10

Proprietaryand confidential — do not distribute © 2015 Abbott Laboratories

MFA‐AOAC, 2015 

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