Determination of Indoxacarb Residue in Foodstuffs of Plant and Animal Origin by GC-ECD and LC-MS/MS

An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.

Research on the Construction of Remote Plant and Animal Hospital in Omnimedia Era

According to characteristics of information communication and sevices in omnimedia era, this paper studied the plan of constructing remote plant end animal hospital, which provided remote diagnosis service by expert team of doctors based on the co-building and sharing medical case resource bases through the reasonable management model on cloud services platform, and discussed the model for service and commerce of remote plant and animal hospital.

Effects of Seasonal and Perennial Grazing on Soil Fauna Community and Microbial Biomass Carbon in the Subalpine Meadows of Yunnan, Southwest China

Grazing and over-grazing may drive changes in the diversity and functioning of below-ground meadow ecosystems. A field soil survey was conducted to compare microbial biomass carbon （Cmin） and soil fauna communities in the two main grassland management systems in subalpine regions of Yunnan Province, China： perennial grazing currently practiced due to increasing herd sizes and traditional seasonal grazing. A three-year exclosure experiment was then conducted to further compare the effects of different grazing practices, including treatments of no mowing, perennial grazing （NM ＋ G）, mowing followed by seasonal grazing （M ＋ G）, mowing and no grazing （M ＋ NG）, and no mowing or grazing （NM ＋ NG）. The comparative survey result revealed that Cmin and total density of soil fauna were significantly lower at a perennially grazed site than at a seasonally grazed site. The experiment results showed that in comparison to non-grazing treatments （M ＋ NG and NM ＋ NG）, grazing （NM ＋ G and M ＋ G） reduced total fauna density （by 150 individuals m-2） and the number of taxonomic groups present （by 0.32 taxa m-2）. Mowing decreased Cmin （by 0.31 mg g-l）. Furthermore, the NM ＋ G treatment （perennial grazing） had the lowest density of Collembola （16.24 individuals m-2）, one of the two most common taxonomic groups, although other taxonomic groups responded differently to the treatments. Treatment effects on soil fauna were consistent with those on above-ground grasses, in which C：N ratios were greatly reduced by grazing, with this effect being the greatest for the NM ＋ G treatment. In contrast, different grazing treatments had little effect on C：N ratio of soil. Furthermore, the traditional grazing method （mowing followed by seasonal grazing） may have less severe effects on some taxonomic groups than perennial grazing. Therefore, an appropriate management should aim to protect soil fauna and microbes in this area from over-grazing and against further degradation.