二氯乙酸质量标准研究

Quality standard for dichloroacetic acid

为了对寡核苷酸固相合成所用的脱保护试剂二氯乙酸做全面的质量控制。实验对二氯乙酸中无机杂质:氯化物、铁盐和重金属等进行了限度控制;建立了离子色谱法含量测定方法。Ionpac AS23(4×250 mm)分析柱;淋洗液为0.8 mmol/L NaHCO3和4.5 mmol/L Na2CO3;抑制型电导检测器。实验结果表明,二氯乙酸的线性方程为:Y=26.01X-0.518 7,(r=0.999 5)。在0.004～1μL/mL浓度范围内呈良好的线性关系,其检测限为0.000 2μL/mL。本方法的精密度和重现性分别为1.26%和0.94%。实验所建立的方法准确,限度合理,能保证二氯乙酸质量和脱保护步骤的顺利进行。

The method for the impurity controlling and content determination of dichloroacetic acid were invesitigated. By ion chromatography （IC） for assay of DCAA. IC was carried out using a ion-pac AS23 column （4 mm × 250 mm） , mobile phase： 4.5 mmol/L Na2CO3/0.8 mmol/L NaHCO3, suppressed conductivity detector. The standard curve equation of DCAA was Y = 26.01X - 0. 518 7, （ r = 0. 999 5）. DCAA showed a good linearity in 0. 004 - 1μL/mL, and detection limit was 0. 000 2 μL/mL. The results indicated that the precision and repeatability were 1.26% and 0. 94% ,respectively,and the analytical recovery was 99.19% （RSD = 1.21% , n = 6）. The method for controlling the quality of DCAA is accurate and can be used in the process of oligonucleotide synthesis.