Comparison of Acoustic Characteristics of Gnathotrichus materiarius and Gnathotrichus sulcatus

As an emerging technology for pest monitoring, sound detection technology has the unique advantages in the field of plant quarantine. Experts at home and abroad have done lots of researches on sound detection technology for trunk borers, and achieved good results. The audible signals of adult Gnathotrichus mate- riarius and G. sulcatus were detected using sound detection method. It was concluded that the feeding and crawling acoustic signals of G. materiarius and G. sulca- tun were significantly different, and the acoustic signals were greatly different even in the same species. In addition, the signal pulse duration and dominant frequen- cy were significantly different. Therefore, it is feasible to monitor trunk borers using sound detection technology.

Rice Straw-Derived Biochar Properties and Functions as Cu(Ⅱ) and Cyromazine Sorbents as Influenced by Pyrolysis Temperature

In this study, biochars from rice straw （Oryza sativa L.） were prepared at 200-600 ℃ by oxygen-limited pyrolysis to investigate the changes in properties of rice straw biochars produced at different temperatures, and to examine the adsorption capacities of the biochars for a heavy metal, copper（II） （Cu（II））, and an organic insecticide of cyromazine, as well as to further reveal the adsorption mechanisms. The results obtained with batch experiments showed that the amount of Cu（II） adsorbed varied with the pyrolysis temperatures of rice straw biochar. The biochar produced at 400 ~C had the largest adsorption capacity for Cu（II） （0.37 mol kg-1） among the biochars, with the non-electrostatic adsorption as the main adsorption mechanism. The highest adsorption capacity for cyromazine （156.42 g kg-1） was found in the rice straw biochar produced at 600 ℃, and cyromazine adsorption was exclusively predominated by surface adsorption. An obvious competitive adsorption was found between 5 mmol L-1 Cu（II） and 2 g L-1 cyromazine when they were in the binary solute system. Biochar may be used to remediate heavy metal- and organic insecticide-contaminated water, while the pyrolysis temperature of feedstocks for producing biochar should be considered for the restoration of multi-contamination.

Determination of Tetracyclines in Honey Using Liquid Chromatography with Ultraviolet Absorbance Detection and Residue Confirmation by Mass Spectrometry

A determination method has been optimized and validated for the simultaneous analysis of tetracycline （TC）, oxytetracycline （OTC）, chlortetracycline （CTC） and doxycycline （DC） in honey. Tetracyclines （TCs） were removed from honey samples by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns and eluted with Na2EDTA-Mcllvaine pH 4.0 buffers. Extracts were further cleaned up by Oasis HLB solid-phase extraction （SPE）, while other solid-phase extraction cartridges were compared. Chromatographic separation was achieved using a polar end-capped C 18 column with an isocratic mobile phase consisting of oxalic acid, acetonitrile and methanol. LC with ultraviolet absorbance at 355 nm resulted in the quantitation of all four tetracycline residues from honey samples fortified at 15, 50, and 100 ng/g, with liner ranges for tetracyclines of 0.05 to 2 μg/mL. Mean recoveries for tetracyclines were greater than 50% with R.S.D. values less than 10% （n= 18）. Detection limits of 5, 5, 10, 10 ng/g for oxytetracycline, tetracycline, chlortetracycline and doxycycline, respectively and quantitation limits of 15 ng/g for all the four tetracyclines were determined. Direct confirmation of the four residues in honey （2-50 ng/g） was realized by liquid chromatography-tandem mass spectrometry （LC/MS/MS）. The linear ranges of tetracyclines determined by LC/MS/MS were between 5 to 300 ng/mL, with the linear correlation coefficient r〉 0.995. The limits of detection of 1 to 2 ng/g were obtained for the analysis of the TCs in honey.