Trimethoprim molecularly imprinted polymer (MIP) was prepared as the coating of stir bar sorptive extraction (SBSE) and applied to the trace analysis of trimethoprim and three sulfonamides in complex samples.The MIP-coating was about 21.5 μm thickness with the relative standard deviations (RSD) of 5.9％ (n=10).It was homogeneous and dense with good thermal and chemical stability.The extraction capability of the MIP-coating was 1.7 times over that of the non imprinted polymer (NIP) coating.The MIP coating exhibited selective adsorption ability to sulfonamides,triazines and methotrexate besides antibacterial synergists.The methods for the determination of trimethoprim and three sulfonamides by MIP-coated stir bar sorptive extraction coupled with HPLC were developed.It was successfully applied to the trace trimethoprim analysis in spiked urine and plasma samples.The linear range was 5 to 200 μg/L and the detection limit was 1.6 μg/L.The recoveries in urine and plasma samples were 84.5％ to 91.7％ with RSDs of 2.9％ -4.4％,71.9％ to 85.1％ with RSDs of 3.0％ -7.3％,respectively.The trimethoprim MIP-coated stir bar was also applied to the trace sulfonamides analysis in spiked milk sample.The linear range was 10-200 μg/L,the detection limit was within the range of 4.5-6.1 μg/L,and the recovery was 83.2％ - 110.2％ with RSDs of 4.1％ -8.0％.

The low mass cutoff ( LMCO) is the main weakness of ion trap when it performs tandem mass analysis by collision induced dissociation (CID). LMCO means that some daughter ions of m/ z are less than about 1 / 3 of the m/ z of parent ion could not be detected during the tandem mass spectrometry processing. A new method which can significantly improve the effect of low mass cutoff was proposed and investigated. By simply changing the scan method of digital potential frequency, some low mass ions can be effectively observed during the tandem mass spectrometric experiment. In the experiment, the frequency of the digital ion trapping power and ion activation power were scanned from lower value to higher value, and some lower mass product ions could be detected during CID process. For example, some lower mass ions were observed during the CID of reserpine precursor ion when the frequency of its digital trapping power was scanned from 500 kHz to 560 kHz. The tandem mass spectra of Reserpine ion showed that the experimental results both from this work and the triple quadrupole mass spectrometer were exactly the same.

An inductively coupled plasma mass spectrometry ( ICP-MS) was developed for the direct determination of Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Mo, Sr, Cd, Ba, Pd, Ag, Sn, Au and Pb in lithium hexafluorophosphate. The sample was dissolved with absolute ethyl alcohol to analyze the above 26 impurity elements in the solution by ICP-MS. The condensation and deposition of high concentrations of carbon in mass cone interface and ion lens, which will decrease the sensitivity of element analysis, can be avoided effectively by introducing O2 to plasma. The mass spectral interferences of polyatomic ions to analytes were corrected by collision reaction cell (CRC). The matrix matching method was used to corrected matrix effect. Satisfactory linearity of each working curve of 26 impurity elements was obtained. The correlation coefficients being over 0. 9995, the detection limits for the investigated elements were in the range of 0. 6-32 ng / L, the relative standard deviation of each element within 2. 5% -7. 3% , and the recovery of each element at 90. 6% -108. 6% . The method had been applied to the determination of trace elements in lithium hexafluorophosphate with satisfactory results.

A molecularly imprinted polymer (MIP) for the selective solid phase extraction of imidacloprid, imidaclothiz, thiacloprid was synthesized by polymerization for 24 h using thiacloprid as template. Dynamic adsorption and selective adsorption test showed that the MIP could quickly adsorb the imidacloprid, imidaclothiz, thiacloprid, with good selectivity for targets. The maximum static adsorption capacity of MIP was 31. 7, 36. 7 and 45. 3 mg / g, respectively. A molecularly imprinted solid phase extraction (MIP-SPE) was developed to separate, clean up and enrich the thiacloprid, imidacloprid and imidaclothiz residue in paddy water, soil, rice, tomato, cucumber. The average recoveries were 80. 2% -98. 8% , with relative standard deviation of 1. 4% -4. 5% . The MIP-SPE was used to analyses the real samples, the result was satisfied.

An electrochemical aptasensor for Pb2+ was constructed based on the layer-by-layer assembly of graphene (GR) and anthraquinone -2-sulfonic acid sodium salt (AQMS) on the surface of Pb2+ aptamer. The mercapto-modified Pb2+ aptamer was first anchored on a gold electrode. Then the highly conductive material of GR was adsorbed on apt through the unique π-π stacking interaction, which was further used for the assembly and signal amplification of the electroactive AQMS. Upon interaction with Pb2+ ions, the apt on the aptasensor undergone conformational switch from a single-stranded form to the G-quadruplex structure, causing the GR assembled with AQMS releasing from the electrode surface into solution. As a result, the electrochemical signal of AQMS on the aptasensor was substantially reduced. Base on this concept, a useful platform for detection of Pb2+ ions was constructed. Under the optimal experimental conditions, the attenuation of peak currents (△Ipa ) showed linear relationship with the logarithm of Pb2+ concentrations (lgCPb2+) over the range from 5. 0×10-10 to 5. 0×10-8 mol/ L. The detection limit was estimated to be 6. 0×10-11 mol/ L.

A Ni-based rare-earth perovskite LaNiTiO3 nanoparticles was synthesized and its catalytic activity was investigated. Based on this, a simple and quick nonenzyme electrochemical sensor was fabricated with stable and reliable performances for the determination of hydrogen peroxide (H2 O2 ). The techniques of X-ray diffraction, FT-IR spectra, transmission electron microscopy, X-ray fluorescene spectroscopy and scan electronmicroscope were used to characterize the composition, structure and morphology of as-synthesized sample. The sensor based on this nanomaterial was investigated and optimized by cyclic voltammetry and current-time techniques. The results showed the working electrode modified with LaNiTiO3 (0. 5 g / L, 8. 0μL) in 0. 1 mol/ L NaOH exhibited good catalytic properties for H2 O2 . Under the optimum conditions, the sensor performed excellent properties, such as quick response time ( about 2 s ), a wide linearity (0. 2 μmol/ L -8. 0 mmol/ L), a low detection limit of 0. 05 μmol/ L ( S / N = 3 ), a high sensitivity of 957 μA (mmol/ L) -1 cm-2 , good reproducibility and anti-interference ability, which was better than those of some other biosensors reported recently. So, it may be used for the analysis and detection of H2 O2 in practical samples such as biomedicine.

The quantitative analysis of biomechanical profiles at the single-cell level can provide additional information. It is usually not available in traditional cell biology approaches, but may be crucial to assess and understand tumor prognosis and response to chemotherapy. In this study, the on-line changes of cell elastic properties after the addition of cancer target drug LHRH-PE40 were monitored by atomic force microscopy ( AFM) on living HeLa cell surface under physiological condition. The results from AFM based force spectroscopy showed that LHRH-PE40 induced a distinct increase of the cell surface elasticity of HeLa cells. The fluorescence images implied that the target drug LHRH-PE40 would affect the re-organization of cell actions, which led to the increase of the elasticity of HeLa cells.

A new magnetic affinity immunoassay (MAIA) strategy based on enzyme-labeled phage displayed antibody was developed. The assay consisted of a sandwich format in which immobilized polyclonal antibody (pcAb) on magnetic microparticle was used for capture probe, and enzyme-labeled phage displayed antibody for specific detection probe to increase enzyme amount and enhance detection signal. By the proposed method,β-bungarotoxin (β-BGT) was successfully detected. A linear relationship between absorbance value and the concentration of β-BGT in the range of 0. 016-62. 5 μg / L was obtained. The linear regression equation was Y=0. 641X+1. 355 (R =0. 9925, n = 13, p<0. 0001) with a detection limit of 0. 016 μg / L. In comparison with the traditional ELISA, this method gave a 10-fold better sensitivity in β-BGT detection. This strategy also gave a 4-fold better sensitivity comparing with the MAIA based on enzyme labeled monoclonal antibody (mcAb). Due to low detection limit, acceptable reproducibility and high specificity, this method holds great promise in toxin trace detection.

An inner-bioreactor rapid filtration sampling probe was designed to resolve the problems of continuous sampling the fermentation broth in on-line measurement the fermentation process. The probe consists of a support, a plug valve, an O-ring, a filter membrane and a pipe cover. It can be inserted directly into the bio-reactor withstanding high-temperature sterilization before fermentation, or preventing the bacteria's invasion during sampling. Fermentation broth in tank is cross-flow filtrated by a cylindrical ceramic membrane which is used as filtration membrane, and then the sterile permeated liquid is transported to the analyzer by a peristaltic pump. The sampling experiments using this device was described for sampling glucose solution indicating it is suitable for fermentation online sampling. The sampling rate is up to 3. 0 mL/ min, glucose permeability maintains 100% , and the delay time caused by the probe is about 2 min.

A bismuth-antimony fire assay method for the preconcentration of ruthenium, rhodium, palladium, iridium and platinum in copper-nickel sulfide ores was developed. 40. 0 g bismuth trioxide, 25. 0 g boric acid, 10. 0 g sodium carbonate and 1. 00 g starch were mixed with 10. 0 g sample in a 120 mL porcelain bowl, which was put in a furnace at 850 ℃. After 20 min the temperature was raised to 1000 ℃ and held for another 40 min, and then the bowl was taken out, with the slag poured, which left the bismuth button to air cooling. A two-step cupellation procedure was developed. During the first step, the bismuth button was cupellated in a magnesia cupel until its diameter reached 5 mm or so, then it was transferred to a crucible cover containing 20 g melting antimony and kept cupellating, at last a bead with a diameter of 1 mm was obtained. The bead was microwave-digested, after cooling down to room temperature, the solvent of which was transferred to a volumetric flask and diluted to 10 ml with water. Pt and Pd were analyzed by inductively coupled plasma-atomic emission spectrometry ( ICP-AES), while 99 Ru, 103 Rh, 191 Ir were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS), with 115 In, 185 Re as internal standard. RSD (n = 12) of the analysis results of five platinum group elements ( PGEs) in standard reference material GBW07196 ranged from 7. 04% to 9. 48% . Under the condition of 10 g sample, the detection limits (ng / g) for PGEs are 0. 027 for Ru, 0. 016 for Rh, 0. 11 for Pd, 0. 10 for Ir and 0. 11 for Pt. The method was applied to the determination of PGEs in GBW07194, GBW07195, GBW07196 with satisfactory results.