title: A comparison study of in-column and on-column detection for electrochromatography.
abstract: Duplex capillary columns, the standard for electrochromatography using optical detection, consist of a packed and an open section. Normally, optical detection is performed in an on-column manner, i.e. at a point right after the packed section. It was deemed that band broadening may take place when an analyte band travels from the packed bed, through the frit and down to the open section. In this study, without using any sintering steps for fritting or window creation, robust packed capillary columns were prepared using transparent capillaries based on single particle fritting technology. The detection point could be easily shifted by simply sliding the transparent column against the ultraviolet (UV) beam. In this way, the band broadening effect was directly evaluated as a function of the detection point, which was positioned before or after the end frit. The consistent van Deemter curves recorded indicate that there was no efficiency difference between the positions investigated. The result proved that the significant band broadening effect previously observed via on-column detection should be caused by the sintered frit used, while the single particle frit made through a purely physical process did not lead to efficiency degradation. The conservative separation performance recorded at different positions around the column's end also suggests the applicability of on-line tandem detection strategy, e.g. UV followed by mass spectrometry (MS), on the same capillary column, which should be a promising approach to mining multiplex detection information from a single microseparation process.
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
authors.forename: Qier
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
authors.forename: Lingjia
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
authors.forename: Zhuoheng
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
authors.forename: Qiuquan
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Chemistry and The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. Electronic address: bozhang@xmu.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
mesh_terms: D053672:Electrochemotherapy / Q000295:instrumentation*; D013058:Mass Spectrometry / Q000295:instrumentation; D015203:Reproducibility of Results
keywords: Capillary column technology; Electrochromatography; On-column detection; Packed columns; Single particle frit; Tandem detection