[Determination of the eliminating ratio of TCM polysaccharide to hydroxyl radical by kinetic fluorescent spectrophotometry].

OBJECTIVE: To explore reaction dynamic of hydroxyl radical (*OH) and salicylic acid,and to determine the elimination ratios of TCM polysaccharide to *OH by kinetic fluorescent analysis. METHODS: The impact dynamics factors of this reaction were studied by fluorescent, such as the reaction of concentration, reaction time and temperature. The dynamical equation was built, a kinetic fluorescent spectrophotometry based on the reaction was developed to determine the elimination ratio. Repetitiveness and reliability of this method were tested by vitamin C. RESULTS: The dynamical equation of reaction rate to salicylic acid was gamma = 0. 9818x -1. 1801 under the condition of lambda ex = 295 nm, lambda em = 411 nm at room temperature, r approximately 1. The 50% elimination ratio (IC50) of TCM polysaccharide of Tangerine peel and Ganoderma lucidum to *OH was 78.01 mg/L and 232.5 mg/L, respectively. The IC50 of vitamin C was 24.52 microg/L, RSD was 0.23% (n = 5). CONCLUSIONS: The method is sensitive and reliable, it can be used to determine the elimination ratio of TCM polysaccharide to *OH.

[Analysis on the volatile oil of Xinhui Pericarpium Citri Reticulatae in different years by GC/MS].

OBJECTIVE: To analyze the difference of the volatile oil of Xinhui Pericarpium Citri Reticulatae in different years. METHODS: The components and contents of the volatile oil of Xinhui Pericarpium Citri Reticulatae were analyzed in different years by GC/MS. RESULTS: The components and contents of the volatile oil of Xinhui Pericarpium Citri Reticulatae changed along with the years. CONCLUSION: With the years' extension, the components of the volatile oil changed slowly during 3 years but quickly after 3 years, a few new components appeared evenly, So there's relevance between using old Xinhui Pericarpium Citri Reticulatae and its component changing.

Dual fluorescence/contactless conductivity detection for microfluidic chip.

A new dual detection system for microchip is reported. Both fluorescence detector (FD) and contactless conductivity detector (CCD) were combined together and integrated on a microfluidic chip. They shared a common detection position and responded simultaneously. A blue light-emitting diode was used as excitation source and a small planar photodiode was used to collect the emitted fluorescence in fluorescence detection, which made the device more compact and portable. The coupling of the fluorescence and contactless conductivity modes at the same position of a single separation channel enhanced the detection characterization of sample and offered simultaneous detection information of both fluorescent and charged specimen. The detection conditions of the system were optimized. K(+), Na(+), fluorescein sodium, fluorescein isothiocyanate (FITC) and FITC-labeled amino acids were used to evaluate the performance of the dual detection system. The limits of detection (LOD) of FD for fluorescein Na(+), FITC, FITC-labeled arginine (Arg), glycine (Gly) and phenylalanine (Phe) were 0.02micromolL(-1), 0.05micromolL(-1), 0.16micromolL(-1), 0.15micromolL(-1), 0.12micromolL(-1) respectively, and the limits of detection (LOD) of CCD achieved 0.58micromolL(-1) and 0.39micromolL(-1) for K(+) and Na(+) respectively.