HPLC analysis of aliphatic and aromatic dicarboxylic acid cross-linkers hydrolyzed from carbohydrate polyesters for estimation of the molar degree of substitution

• Published in: Carbohydrate polymers Vol. 59; no. 3; pp. 305 - 312
• Main Authors: Sarkar, Arindam Basu, Kochak, Gregory M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 18.02.2005; Elsevier Science
• Subjects: Applied sciences; Carbohydrate polyesters; chemical analysis; Dicarboxylic acids; Exact sciences and technology; high performance liquid chromatography; HPLC; Molar degree of substitution; Natural polymers; Phenacyl ester derivatives; Physicochemistry of polymers; Starch and polysaccharides; Molar degree of substitution; Carbohydrate polyesters; Phenacyl ester derivatives; Dicarboxylic acids; HPLC; Ester polymer; HPLC chromatography; Routine analysis; Crosslink agent; Experimental study; Analysis method; Hydrolysate; Dicarboxylic acid; Qualitative analysis; Measurement accuracy; Starch derivative
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2004.10.002

Quantitative analysis of carboxylic acids in hydrophilic matrixes remains a challenge despite the introduction of derivatization reagents for carboxylic acids nearly three decades ago. Analysis of many bifunctional ester forming polymer cross-linkers are additionally complicated by the their amphiphatic character. We report a sensitive and selective HPLC method to quantify organic dicarboxylic acids resulting from the hydrolytic degradation of cross-linked carbohydrate polyesters. An important group of cross-linkers encompassing C 7–C 10 aromatic and non-chromophoric aliphatic diacid chlorides were investigated. Specific validation is reported for terephthalic acid, diethylmalonic acid and sebacic acid. Linear calibration curves were obtained in the 0.5–15.0 μg/ml range corresponding to a mass fraction of 0.05–1.5% diacid to polyester. The accuracy and precision in this range was 94.4–114.1 and 6.1–24.8% RSD, respectively. This method is suitable for the routine determination of the molar or mass degree of substitution in carbohydrate polyesters.