On-line pre-treatment, separation, and nanoelectrospray mass spectrometric determinations for pesticide metabolites and peptides based on a modular microfluidic platform

Abstract

In order to address time-consuming sample pre-treatment and separation prior to mass spectrometry (MS) identifications, highly integrated chips were developed, but damage to any functional unit in these chips would result in complete replacement. Herein, we propose a modular microfluidic platform comprising pre-treatment, liquid chromatography (LC) separation and nanoelectrospray ionization (nESI) chips for on-line enrichment, separation and nESI MS detection of pesticide metabolites and peptides. The pretreatment chip is applicable in enriching pyridalyl and its metabolites, and it achieves optimal desalination efficiency, 98.5%, for polymerase chain reaction products. Additionally, the LC separation chip was fully characterised, and it demonstrated satisfactory separation efficiency, quantification ability and pressure durability. Finally, the modular microfluidic platform was used to identify the peptides in trypsin-digested casein. Four additional peptides were identified, indicating an improvement in detection ability compared with using off-line zip tips coupled with MS investigations. Because the proposed modular platform can significantly reduce manual work, it would be a potential tool to achieve high throughput and automatic MS identifications with low sample consumptions. † Electronic supplementary information (ESI) available: One PDF le provides supporting information for pre-treatment and separation modules congurations, instrumental setup of the modular platform, PCR experimental details, and identication of reserpine with the proposed platform. See

Research progress on pesticide residue detection based on microfluidic technology

“…Combined with GC and LC chromatographic separation technology, it has been included in the technologies of various countries as a standard method for detecting agricultural residues. A microfluidic chip combined with ESI-MS provides an analytical platform with high detection throughput and low sample consumption [31]. For example, mesoporous silica nanofluidic channels were used for the rapid enrichment/extraction of trace OPs from aqueous solution into ethanol.…”

Modular Microfluidics: Current Status and Future Prospects

“…The authors pointed out that the modular design could reduce the risk of rework of the whole system due to a single point of failure, as well as reduce the cost of trial and error. Hao et al studied a modular microfluidic system for mass spectrometry [80]. The semiautomatic detection of insecticides and insecticide metabolites was achieved by serial connection of the pretreatment module, gas chromatography separation module, and nano-electrospray ionization module, avoiding a tedious manual operation process.…”

Nano liquid chromatography columns

“…Hao et al have developed a modular microfluidic platform composed of independent pretreatment, LC separation, and nESI chips, for determination of pesticide metabolites and peptides 110 . The lengths of the rectangle regions in pre-treatment and LC separation modules were 2.5 mm and 20 mm, respectively.…”