Cao Jiaxing, Hang Yiping, Lu Jianping, Tong Zhangfa
College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
Se Pu. 2010 Sep;28(9):893-7.
A method was established for the determination of main nonnitrogenous organic acids (including acetic, lactic, succinic, maleic, tartaric, oxalic, fumaric, citric, and aconitic acids) and three inorganic anions (Cl-, SO4(2-) and PO4(3-)) in sugarcane molasses and molasses alcohol waste by ion chromatography with solid-phase extraction. The diluted sample solution was purified by strong anion exchange (SAX) solid-phase extraction (SPE) in a small packed column to remove most of sugar, pigment and other interfering matrices. The eluate obtained from the column was rinsed with diluted KOH solution and filtered through a 0.45 microm inorganic membrane, finally separated on an anion column of IonPac AS15 with the gradient elution of KOH solution and determined with a suppressed conductivity detector. The pretreatment and procedures of SPE for separating organic acids and inorganic anions from their matrix were investigated. The detection limits wee d less than 0.20 mg/L. The relative standard derivations were less than 6.7%. The organic acids and inorganic anions in three real samples (two sugarcane molasses samples and an alcohol waste sample) were determined, the recovery ranges were from 94% to 109%. The method shows good precision and linearity.
建立了一种采用离子色谱-固相萃取法测定甘蔗废蜜和废蜜酒精中主要非氮有机酸（包括乙酸、乳酸、琥珀酸、马来酸、酒石酸、草酸、富马酸、柠檬酸和乌头酸）及三种无机阴离子（Cl-、SO4(2-)和PO4(3-)）的方法。稀释后的样品溶液通过小填充柱中的强阴离子交换（SAX）固相萃取（SPE）进行纯化，以去除大部分糖、色素和其他干扰基质。从柱中获得的洗脱液用稀释的KOH溶液冲洗，并通过0.45μm无机膜过滤，最后在IonPac AS15阴离子柱上用KOH溶液梯度洗脱进行分离，并用抑制电导检测器进行测定。研究了从基质中分离有机酸和无机阴离子的SPE预处理和程序。检测限小于0.20mg/L。相对标准偏差小于6.7%。测定了三个实际样品（两个甘蔗废蜜样品和一个酒精废样品）中的有机酸和无机阴离子，回收率范围为94%至109%。该方法具有良好的精密度和线性。
