重烷基苯磺酸盐组分分析

Component Analysis of Heavy Alkyl Benzene Sulfonate

用电喷雾电离质谱(ESI/MS)法,分别在正、负离子模式下测定了几种重烷基苯磺酸盐(HABS)的组成。在负离子模式下,各组分主要以[M-Na]-的形式被检测到,在正离子模式下,各组分主要以[M+Na]+的形式被检测到。结果表明,两种模式分析结果基本相同,但正离子的响应灵敏度小于负离子的。谱图分析结果表明,HABS主要成分是一系列不同碳链长度的单烷基苯磺酸盐。金桐2#、金桐1#、南京1#重烷基苯磺酸盐以及ABS的最大组分是碳链长度分别为C17、C13、C13、C12的单烷基苯磺酸盐。根据谱图还可求出各组分的相对含量和摩尔质量,并据此计算出HABS的平均摩尔质量,其值小于由两相滴定法测定的结果。

Several kinds of HABS were identified by positive and negative ions electrospray ionization/mass spectra （ESI/MS） methods. Individual component could be detected as cationic ion [M＋Na]＋ in positive ion mode and as anionic ion [M-Na]-in negative ion mode. The results obtained in both modes were almost the same, but the detection sensitivity of positive ESI/MS was significantly lower than negative ESI/MS. The analysis results of Spectrogram showed that the main components of HABS were a series of the single alkyl-benzene sulfonate with different carbon chain length, and the maximum component of Jintong 2#, Jintong 1#, Nanjing 1# and ABS was single alkyl-benzene sulfonate with a carbon chain length of C17, Cl3, C13, C12 respectively. The relative quantity and molecular weight of each component could be calculated from the Spectrograms of HABS, from which the average molecular weight of HABS could be found, which was a little lower than that from two-phase titration.