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High speed,high mobility and high adaptability become the inevitable developing trend of quadruped robot,bionic joints as an important basis of moving parts,plays an important role about the kinematics and dynamics research of quadruped robot. Specific from four aspects of flexible pneumatic bionic joints,hydraulic damping bionic joints,series-wound elastic drive bionic joints and flexible variable stiffness bionic joints,the research status of quadruped robot bionic joints is summarized,and the various types of bionic joint defects are accurately analyzed. Finally,the future develop trend of quadruped bionic robot joints is described.With the deepening of the research,the quadruped robot bionic joint will have widely application prospect in production services,human exploration,future war and other special fields inevitably.

A method was established for the determination of streptomycin (STR) and dihydrostreptomycin (DHS) in pollens based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was extracted and cleaned-up by a C18 solid phase extraction cartridge. The separation was carried out on a Protemix WCX-NP5 column (100 mm x 2.1 mm, 5 microm) with a gradient elution using 5% (v/v) formic acid, 20 mmol/L ammonium acetate and methanol as mobile phases. The analysis of streptomycin and dihydrostreptomycin was performed under electrospray positive ionization mode. The limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) for the both were 5 microg/kg and 10 microg/kg, respectively. Good linearities (r > 0.99) were achieved for the target compounds over the range of 10-200 microg/L. The recoveries at three spiked levels (10, 20, 50 microg/kg) in the blank matrices, such as pollen pini, corn pollen, camellia pollen, sunflower pollen, rape pollen and bee pollen, were from 76.8% to 100.3% with the relative standard deviations varied from 3.70% to 12.6%. The method is accurate, practical, and can be applied to most of the contaminated matrices. With this method, heptafluorobutyric acid is not required as mobile phase which is harmful to MS spectrometer.

Bisphenol A, tetrabromobisphenol A and alkylphenols have received much attention in recent years because of their endocrine disrupting effects to aquatic ecosystem. The fate of these compounds in sewage treatment plant which is important to deal with this kind of compounds has significance on the study of exposure levels of the target compounds in the environment, and the development of analytical method is the basis on the above study. An analytical method based on liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) with negative ionization mode has been developed for measuring bisphenol A, tetrabromobisphenol A and six alkylphenols in raw and treated sewage samples. The target compounds were separated on a ZORBAX Eclipse Plus C18 column (150 mm x 2.1 mm, 3.5 microm) with mobile phases of acetonitril and 0.02% (v/v) ammonia. Analyte confirmations were performed under multiple reaction monitoring (MRM) mode and the eight compounds were separated within 11 min. The calibration curves were linear in the range of 1 - 100 microg/L (R2 > or = 0.998). The quantification limits of the eight compounds were 2.0 - 20 ng/L. The recovery experiments were performed with samples spiked at the levels of 0.2, 2 and 20 microg/L, and the recoveries for the target compounds were in the range of 64.3%-118.0%, 65.9% - 100.5% and 70.3%-102.7% (RSD < 7.1%, n = 3), respectively. Based on the analytical method, the raw and treated sewage samples from an industrial park of Jiangsu Province were analyzed. Five compounds were detected in the water outlet in the range of 11.9-3 015.3 ng/L. It shows that the method is simple, selective, sensitive and can be used to analyze the water samples of sewage treatment plant containing alkylphenols.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of five pyrrolizidine alkaloids (PAs) (monocrotaline, senkirkine, retrorsine, seneciphylline and senecionine) in honey. The honey samples were dissolved in 0.1 mol/L hydrochloric acid solution and a strong-cation exchange column was used to purify and concentrate the target analytes. The separation of the analytes was carried out on a Phenomenex C18 column (100 mm x 4.6 mm, 2.6 microm) using the mobile phases of acetonitrile and 5 mmol/L ammonium acetate-0.1% (volume percentage) formic acid aqueous solution with gradient elution. The separated compounds were detected in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI+). The calibration curves were of good linearity in the range of 1-100 microg/L (r > 0.99). The limit of quantification of the method was 1.0 microg/kg. The average recoveries were between 73.1% to 107.1% at three spiked levels (1, 20 and 50 microg/kg) with the relative standard deviations (RSDs) in the range of 4.1% to 17.0%. The proposed method was applied to different kinds of honey from China, New Zealand, Spain and Australia. The samples included rape, vitex, sunflower, cotton, tilia tree, date, acacia, buckwheat, manuka and eucalyptus honey. Monocrotaline, senkirkine and retrorsine were not detected in the collected honey samples. However, seneciphylline and senecionine were found in most of the honey samples. The concentrations of seneciphylline and senecionine were 11.0 -31.1 microg/kg and 8.3-29.1 microg/kg, respectively.

A method for the determination of 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) in human urine, which is the main metabolite of chlorpyrifos, has been established employing ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/ MS). The urine samples were prepared by liquid-liquid extraction with dichloromethane-ethyl acetate (20: 80, v/v) solution followed by the separation with the gradient elution of acetonitrile-water on an ACQUITY UPLC BEH C18 column. The analyte was detected by tandem mass spectrometry under the negative ion mode with the electrospray ionization (ESI) source and the selective ion recording (SIR) mode. Under the optimized conditions, the calibration curve was linear in the range of 0.005 -0.4 mg/L. The limit of detection was 0.41 microg/L. The average recovery was 97.9%. The intra- and inter-day precisions calculated with RSDs were all within 15% at each quality control (QC) level. The developed method is simple, sensitive, accurate and repeatable, which has been successfully applied to determine the exposure level of 3,5,6-TCP in the real samples of human urine. The results show that this method is supportive for the exposure assessment in human health risk analysis and monitoring the biological burden of chlorpyrifos.

A method was established for the determination of deoxynivalenol (vomitoxin) in grain and its products based on solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was firstly extracted by acetonitrile-water (84:16, v/v). The extract was then cleaned-up by an HLB solid phase extraction cartridge. The separation was carried out on a Phenomenex Kinetex C18 column (100 mm x4. 6 mm, 2.6 microm) with a gradient elution using 0.3% per hundred ammonia solution-acetonitrile as mobile phases. The analysis of deoxynivalenol was performed under electrospray negative ionization mode. The limit of detection (LOD, S/N= 3) and the limit of quantification (LOQ, S/N = 10) were 20 microg/kg and 50 microg/kg, respectively. A good linearity (r > 0.99) was achieved for the target compound over the range of 20-1000 pg/L. The recoveries at the three spiked levels (50, 100, 500 microg/kg) in the blank matrices such as flour, barley, soybean, rice, cornmeal, cassava and wheat, were varied from 75.6% to 111.0% with the relative standard deviations no more than 13. 0%. The method is accurate, efficient, sensitive and practical. The cost of pretreatment is obviously reduced by replacing immunoaffinity columns and Mycosep columns with HLB columns which have the same purification effect.