Reversed-Phase Functionalised Multi-lumen Capillary as Combined Concentrator, Separation Column, and ESI Emitter in Capillary-LC–MS

Open tubular liquid chromatography: Recent advances and future trends

“…The extractive OT column allowed filtration/filter back-flushing plumbing, with backpressure ≈35 bar at 0.5 L/min, for fast loading and sufficient refocusing. Likewise, Rodriguez et al [73] assessed the use of a functionalized multi-lumen capillary (126 parallel channels of 4.2 μm i.d.) with C18 as extractor/pre-concentrator, analytical column, and ESI emitter.…”

Nano liquid chromatography columns

“…The ID of the commercial nanospray emitters is not compatible with the narrow ID columns. In order to maintain the high efficiency of the narrow ID open tubular format, but having larger sample capacity and ease MS detection, Paull and coworkers have explored the use of multichannel (multilumen) capillaries 83,84 . They used photonic crystal fibre which contained 126 internal parallel 4 µm channels, with a porous poly(styrene-co-divinylbenzene) layer, and report run-to-run retention time repeatability below 1% 83 .…”

“…They used photonic crystal fibre which contained 126 internal parallel 4 µm channels, with a porous poly(styrene-co-divinylbenzene) layer, and report run-to-run retention time repeatability below 1% 83 . In the more recent paper 84 , the same group reports a multi-lumen capillary (also with 126 parallel channels of 4.2 μm ID) with a C18functionalised silica porous layer OT column for both on-capillary preconcentration and separation, followed by MS detection. Following modification, 100% of the channels displayed a homogenous porous silica layer, 257 ± 36 nm thick.…”

“…Vehus et al used a high sample capacity 50 μm × 40 mm (PS-OD-DVB) monolithic trap column with sample capacity (>2000 ng on a 10 cm column; comparable to the capacity of commercial particle-packed columns) in combination with a 10 μm × 3000 mm OT column functionalized with octadecyl groups bound to a silica skeleton that coats the wall of the column 76 . The approach used by Rodriguez et al 84 , and Ribeiro da Silva et al 85 may also be a solution to look into.…”

Extension of hydrodynamic chromatography to DNA fragment sizing and quantitation

“…In 1994 [ 21 ] it was named end-labeled free-solution electrophoresis. With the development of micro- and nano-fabrication technology, entropic trapping [ 23 , 24 ] and DNA prism [ 25 , 26 ] have also been utilized to analyze DNA fragments in free solution. High-performance liquid chromatography (HPLC) has been also applied for DNA analysis in free solution with various modes, such as ion-exchange chromatography [ 27 ], ion-pair reversed-phase chromatography [ 28 , 29 ], size exclusion chromatography [ 30 , 31 , 32 ], slalom chromatography [ 33 , 34 ] and HDC [ 35 , 36 ].…”