Hopper Kristy G, Leclair Holly, McCord Bruce R
Graduate and Undergraduate Program, Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA.
Talanta. 2005 Aug 15;67(2):304-12. doi: 10.1016/j.talanta.2005.01.037. Epub 2005 Feb 24.
A novel electrolyte has been developed for the simultaneous separation of cations and anions in low explosive residue by capillary electrophoresis. This electrolyte contains 15mM alpha-hydroxyisobutyric acid (HIBA) as the buffer, 6mM imidazole as the cation chromophore, 3mM 1,3,6-naphthalenetrisulfonic acid (NTS) as the anion chromophore, 4mM 18-crown-6 ether as a cation selectivity modifier, and 5% (v/v) acetonitrile as an organic modifier. The pH was adjusted to 6.5 using tetramethylammonium hydroxide (TMAOH), an electroosmotic flow modifier. The method was optimized by varying the concentrations of alpha-HIBA, imidazole, and 1,3,6-NTS at three different pH values. The results provided a simultaneous indirect photometric analysis of both anions and cations with detection limits ranging from 0.5 to 5ppm for anions and from 10 to 15ppm for cations with a total run time of under 7min. The method was then applied to the analysis of Pyrodex((R)) RS and black powder, as well as several smokeless powders. The results obtained were consistent with previously reported results for separate anion and cation analysis and provide a faster, more complete analysis of each sample in a single chromatographic run.
一种新型电解质已被开发出来，用于通过毛细管电泳同时分离低爆速残留物中的阳离子和阴离子。这种电解质包含15mMα-羟基异丁酸（HIBA）作为缓冲剂、6mM咪唑作为阳离子发色团、3mM 1,3,6-萘三磺酸（NTS）作为阴离子发色团、4mM 18-冠-6醚作为阳离子选择性修饰剂以及5%（v/v）乙腈作为有机修饰剂。使用电渗流修饰剂氢氧化四甲铵（TMAOH）将pH调节至6.5。通过在三个不同pH值下改变α-HIBA、咪唑和1,3,6-NTS的浓度对该方法进行了优化。结果实现了对阴离子和阳离子的同时间接光度分析，阴离子的检测限为0.5至5ppm，阳离子的检测限为10至15ppm，总运行时间不到7分钟。然后将该方法应用于分析派罗代克斯（Pyrodex((R))）RS、黑火药以及几种无烟火药。获得的结果与先前报道的单独阴离子和阳离子分析结果一致，并能在一次色谱运行中对每个样品进行更快、更全面的分析。
