On-Line Sample Treatment LC System for MS Compatibility

Abstract

In the present work, a new liquid chromatography-mass spectrometry (LC-MS) system with on-line pretreatment using column switching and a dilution function was developed. This system can be used under conventional high-performance liquid chromatography (LC) separation conditions, including mobile phases containing phosphate buffer. The built-in autodilution function greatly improves the trapping efficiency for target compounds, followed by desaltation that optimizes the ionization conditions for MS analysis. This fully automated two-dimensional LC system interfaced with mass spectrometry provided a powerful tool for the determination of impurity profiles in pharmaceutical research and the identification of traditional Chinese medicine in natural products.

Quantitative Analysis of Chloramphenicol in Royal Jelly by Column-switching LC-MS/MS Using a Pretreatment Column with a Higher-pressure Capability

“…Liquid-contacting parts, such as the valves at the autosampler, the inner wall of tubings between the autosampler and the switching valve, inner parts of the switching valve, are potential sources of cross-contamination of the target compound in the column-switching LC system. [28][29][30] Carryover after injection of the sample with a high-concentration target compound would cause inaccurate quantitative results at the next injection. In order to assess any cross-contamination of the system, a blank sample (water/methanol) was injected after the analysis of a high-concentration (10 ng/mL) sample.…”