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Wang Q.,Jiangnan University | Xie Y.-F.,Jiangnan University | Zhao W.-J.,Su Zhou Wei Mu Intelligent System Ltd. | Li P.,Su Zhou Wei Mu Intelligent System Ltd. | And 2 more authors.
Analytical Methods

A fast and quantitative method for the detection of biogenic amines based on the microchip-based high-field asymmetric waveform ion mobility spectrometry (FAIMS) technique was established for evaluating the degree of spoilage of pork stored at room temperature. Trimethylamine (TMA) was selected as a good indicator for its volatility and high proton affinity. Analysis of standard TMA showed the same characteristic peak with the pork sample. The limit of detection of the system for TMA dissolved in deionized water, with 100 μL of 8 mol L-1 NaOH, was 3 ng and the measurement was accomplished within 15 s. The relative standard deviation (RSD) was 6.20%. The delivery of the sample gas was based on the dynamic headspace method. The effect of the storage time on the formation of biogenic amines was examined, and not surprisingly, the content of TMA increases over time. The total volatile basic nitrogen (TVB-N) was measured simultaneously based on the classical semi-micro Kjeldahl method. A good correlation coefficient between these two methods was obtained, the correlation coefficient was 0.952. Therefore the microchip-based FAIMS technique provides a quantitative classification of the spoilage or freshness of pork, especially when a rapid detection is needed. © The Royal Society of Chemistry 2014. Source

Han K.,CAS Lanzhou Institute of Chemical Physics | Han K.,Su Zhou Wei Mu Intelligent System Ltd. | Liu S.,CAS Lanzhou Institute of Chemical Physics | Tang S.,CAS Lanzhou Institute of Chemical Physics | And 2 more authors.
Analytical Methods

A zirconia coated column was prepared for capillary electrophoresis separation based on a mussel adhesive protein inspired polydopamine coating for the first time. Polydopamine, formed by the spontaneous oxidative polymerization of dopamine under alkaline conditions, was used to immobilize zirconia onto the inner surface of a capillary via a liquid phase deposition process. During the formation of zirconia, the outer hydroxyl groups of the polydopamine layer can chelate with Zr4+ to boost nucleation and growth of zirconia. The existence of the zirconia coating was successfully confirmed by using X-ray photoelectron spectroscopy and a comparative study of electroosmotic flow. Furthermore, the zirconia coated capillary was applied in the separation of inorganic anions and alkaloids and baseline separations were achieved with good reproducibility and stability. Therefore, the presented method is anticipated to be a promising preparation technology for metal oxide coated columns, characterized by a simple preparation process, mild reaction conditions and high efficiency. © 2012 The Royal Society of Chemistry. Source

Li J.,Su Zhou Wei Mu Intelligent System Ltd. | Zhao W.,Su Zhou Wei Mu Intelligent System Ltd. | Li L.,Zhejiang University | Li X.,Su Zhou Wei Mu Intelligent System Ltd. | And 2 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities

Field asymmetric ion mobility spectrometry(FAIMS) technique was introduced into the sensitive and rapid analysis of four synthetic pigments for the first time. The chrysoidin, malachite green, rhodamine B and methyl red were detected by a co-developed thermal desorption-FAIMS(TD-FAIMS) system. The ion characteristic signals of synthetic pigments were acquired under the optimized conditions with the injection temperature of 160°C and the carrier gas flow rate of 1.6 L/min. Compensation voltage(CV) values with different modes were adopted for qualitative measurement. FAIMS detection signals in positive mode appeared at CV=0.41 and 0.89 V for chrysoidine and rhodamine B, respectively, while negative mode detection signals of methyl red and malachite green appeared at CV=0.67 and 0.02 V, respectively. Using external stan-dard method for quantitative measurement, the linear relationship(R2) was above 0.9967. The limits of detection(LOD) were 2.5-10 μg/L, and limits of quantification(LOQ) were 5-20 μg/L, respectively. The average recoveries were higher than 78.2% and the relative standard deviation(RSD) was less than 8.0%. This study laid a foundation for the application of FAIMS technique to rapid detection of synthetic pigments. The FAIMS instrument, which are highly sensitive, simple and fast responsive, demonstrated huge potential in the rapid analysis of synthetic pigments. Source

Wang X.,Zhejiang University | Zhao W.,Su Zhou Wei Mu Intelligent System Ltd. | Li L.,Zhejiang University | Li P.,Suzhou University | And 2 more authors.
Analytical Methods

Sulfites (sulfur dioxide) and inorganic sulfites are types of food additives and preservatives, widely used in the production of food and herbal medicines (HMs). However, the overingestion of sulfites and its associates are harmful to human health and may cause medical complications. Various methods and instruments have been developed for measuring sulfites in foods and HMs, but they typically suffer from many issues, such as high detection limitation, inaccurate and non-reliable results, time and labor-intensive sample preparation, and high cost. Herein, we present a fast, sensitive, and quantitative method to determine sulfites in HMs using field asymmetric-wave ion mobility spectrometry (FAIMS) coupled with a headspace bubbling method. The headspace air bubbling method is effective and efficient at generating stable sulfur dioxide (SOinf2/inf) in the gas phase for FAIMS analysis. It allows sulfites with a concentration down to 1 mg kgsup-1/sup to be easily detected by this new method in 20 min, much shorter than with current technologies. The limits of detection (LOD) and limits of quantification (LOQ) are 1 mg kgsup-1/sup and 3 mg kgsup-1/sup in HMs, respectively. The new method is of great significance to ensure medical safety and for HM production quality control. © 2015 The Royal Society of Chemistry. Source

Zhang J.,Su Zhou Wei Mu Intelligent System Ltd. | Li L.-F.,Zhejiang University | Guo D.-P.,Zhejiang University | Zhang Y.,Su Zhou Wei Mu Intelligent System Ltd. | And 3 more authors.
Fenxi Huaxue/ Chinese Journal of Analytical Chemistry

An in-situ analytical procedure employing silicon chip based ultra high field asymmetric waveform ion mobility spectrometry (FAIMS) via direct sniffing was developed for the determination of 10 listed hazardous chemicals which are prohibited for public transportation in China. The sample introduction temperature was set at 50 °C. The carrier gas flow rate and the sample flow rate were 1500 and 100 mL min-1, respectively. Recognition algorithm was also developed for the FAIMS fingerprint spectral. Ten kinds of chemicals were resolved with high reproducibility at the concentration from 100 ppb to 20 ppm. In comparison with the current competing instruments, the microchip based FAIMS instrument, which features its simplicity, high sensitivity and selectivity, fast response and free of sample pretreatment, opens up new applications in the field of public security and homeland security. Copyright © 2013, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. Source

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