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Better sensitivity and interface of ambient sampling/ionization mass spectrometry remain a challenge. Herein, a novel, plasma-based, ambient sampling/ionization/transmission (PASIT) integrated source in a pin-to-funnel configuration was developed for the sensitive analysis of complex samples. With the funnel sleeve directly affected by direct-current discharge plasma, PASIT combines the ability to sample/ionize analyte molecules and then efficiently collect/transport charged mass species under atmospheric pressure and consequently shows an improved sensitivity. The integrated source enhances the signal intensity by more than 2 orders of magnitude compared with the previous pin-to-plate plasma source without significant background addition. A surface limit of detection (LOD) of 130 fmol mm-(2) (S/N = 3) has been achieved for clenbuterol on filter paper with an argon carrier gas. Demonstrated applications include the direct determination of active ingredients from drugs and symbolic compounds from natural plants and cholesterol from mouse brain tissue sections.

Accurate mass information is of great importance in the determination of unknown compounds. An effective and easy-to-control internal mass calibration method will dramatically benefit accurate mass measurement. Here we reported a simple induced dual-nanospray internal calibration device which has the following three advantages: (1) the two sprayers are in the same alternating current field; thus both reference ions and sample ions can be simultaneously generated and recorded. (2) It is very simple and can be easily assembled. Just two metal tubes, two nanosprayers, and an alternating current power supply are included. (3)With the low-flow-rate character and the versatility of nanoESI, this calibration method is capable of calibrating various samples, even untreated complex samples such as urine and other biological samples with small sample volumes. The calibration errors are around 1 ppm in positive ion mode and 3 ppm in negative ion mode with good repeatability. This new internal calibration method opens up new possibilities in the determination of unknown compounds, and it has great potential for the broad applications in biological and chemical analysis.

Chinese liquors are often a very important part of social event in China. Driven by high profit, some illegal traders often use inferior liquors instead of the products with high quality to cheat the customer. Therefore, it is highly required to authenticate Chinese liquors. In this paper a novel method based on ambient glow discharge ionization mass spectrometry has been developed to differentiate Chinese liquors. Volatile components from liquor samples were ionized by the plasma generated by glow discharge and then detected by a commercial linear ion trap mass spectrometer. Consequently, the fingerprint mass spectra of several Chinese liquors were obtained. Combined with principal component analysis, this new method was successfully applied to differentiate different brands of Chinese liquors without any sample pretreatment. Compared with conventional methods, this novel method has the advantages of easy operation, high speed, and high efficiency, which make it a potential tool in the fields of food safety, atmosphere chemistry.

With the development of material science and the practical needs of the polymer industry, rapid characterization of synthetic polymers using mass spectrometry is of sustainable interest. Herein a new method for characterizing synthetic polymers using thermal-assisted atmospheric pressure glow discharge mass spectrometry (TA-APGD-MS) is established. After illustration of the mechanism of ion formation, typical polymer samples such as polystyrene (PS), polyoxymethylene (POM) and poly (butanediol succinate) (PBS) were directly characterized at the molecular level using TA-APGD-MS. The thermal degradation products of synthetic polymers including monomer units and/or other fragments were rapidly detected by tandem mass spectrometry, providing rich information about the chemical composition for the structural characterization of homo- and co-polymers. The result suggests that TA-APGD-MS allows direct and rapid analysis of both synthetic homo-polymers and co-polymers under ambient conditions without any sample pretreatment. This method features high throughput, high sensitivity and rich information, showing promising applications in polymer science.