OIV标准葡萄酒中山梨酸的检测方法.pdfVIP

COMPENDIUM OF INTERNATIONAL ANALYSIS OF METHODS - OIV Sorbic Acid –Capillary Electrophoresis Method OIV-MA-AS313-18 Type IV method Determination of sorbic acid in wines by capillary electrophoresis (Resolution Oeno 4/2006) 1 Scope The present method is used to determine the sorbic acid in wines in a range from 0 to 300 mg/l. 2 Principle The negatively charged sorbate ion naturally enables easy separation by capillary electrophoresis. At the capillary outlet, detection is carried out in the ultraviolet spectrum at 254 Nm. 3 Reagents and products 3.1 Reagents 3.1.1 Sodium dihydrogenophosphate [10049-21-5] purity 96% 3.1.2 Sodium hydrogenophosphate [10028-24-7] purity 99% 3.1.3 Sodium hydroxide [1310-73-2] purity 97% 3.1.4 Hippuric sodium [532-94-5] purity 99% 3.1.5 Demineralised water ( 15 MOHMS) or double-distilled 3.2 Migration buffer solution The migration buffer is made up in the following way: Sodium dihydrogenophosphate (3.1.1): 5 mM Sodium hydrogenophosphate(3.1.2) 5 mM 3.3 Internal standard Hippuric spdium (3.1.4) in an aqueous solution 0.5 g.L-1 3.4 Rinse solutions 3.4.1 Sodium hydroxide (3.1.3) N/10 3.4.2 Sodium hydroxide (3.1.3) N OIV-MA-AS313-18 : R2006 1 COMPENDIUM OF INTERNATIONAL ANALYSIS OF METHODS - OIV Sorbic Acid –Capillary Electrophoresis 4 Sample preparation The wine samples are prepared as follows, which involves a 1/20 dilution: Wine to be analyzed: 0.5 ml Sodium hydroxide (3.1.3): 0.5 ml Internal standard (3.1.4) with 0.5 g. L-1: 0.5 ml Qsp 10 ml with demineralized water (3.1.5) 5 Operating conditions 5.1 Conditioning the capillary Be