我国农药残留分析技术发展概述

本文概述了近年我国常用的农药残留样品前处理技术和检测技术并简要介绍了90年代以来国际上发展起来的一些农药残留样品前处理新技术和检测新技术。     

基于PLC自动嫁接机控制系统设计

为提高蔬菜嫁接作业效率、降低人工劳动强度,研究瓜茄科贴接式自动嫁接机控制系统。根据嫁接机实际使用要求,结合限位传感器输入信号以及输出执行元件特点,采用三菱FX1N系列PLC作为嫁接机控制器;依据嫁接机作业流程以及使用调试要求,采用SFC编程语言编写控制程序,提供单步运行和连续运行两种工作模式选择。测试试验表明,嫁接机作业效率可达653株/h。     

农民专业合作社开展有机茶认证的探讨

国际上称之的小农户组织,在国内则是农民专业合作社。中国农业科学院茶叶研究所有机茶研究与发展中心（OTRDC）在国际商品共同基金的资助下,对云南省双江县亥公村农民专业合作社持续开展了有机茶认证。农民专业合作社获得有机认证的关键因素是：有效的内部控制系统;与具有市场开拓能力和社会责任感的企业建立双赢合作关系;认证机构按照标准要求实施认证。     

In vitro proliferation and minimum growth storage of fraser photinia: Influences of different medium,sugar combinations and culture vessels

Protocols for the in vitro proliferation and storage of fraser photinia were developed by comparing 6-benzyladenine (BA) concentrations (0.5–4 mg/L) together with different media formulations [Murashige and Skoog (MS) media and Quoirin and Lepoivre (QL) media], sugar combinations (sucrose and mannitol), culture vessels (baby food jars and vitrovents) and methods (synthetic seed technology and slow growth storage). The best responses in terms of both proliferation percentage and multiple shoot formation were obtained in QL medium containing 1 mg/L BA. Synthetic seed production was optimized by encapsulating shoot apices in 3% sodium alginate. Encapsulated shoot apices could be maintained up to 6 months at 4 °C in dark with 91.6% sprouting in MS medium. Microshoots were stored at 4 °C up to 15 months on sucrose and mannitol containing QL medium in both baby food jars and vitrovents without subculture. The stored material could be recovered and multiplied normally in 1 mg/L BA supplemented QL medium. Both in vitro propagated and conserved microshoots were rooted (∼75%) on QL medium with 1 mg/L indole butyric acid (IBA). Optimized synthetic seed and slow growth storage system can be used for short and medium-term storage of fraser photinia germplasm.     

Polyprenols from the needles of Taxus chinensis var. mairei

Polyprenols with various pharmacological activities were first isolated from Taxus chinensis var. mairei, which is native to China, and were identified by a high performance liquid chromatography/mass spectrometry (HPLC/MS), (1)H nuclear magnetic resonance ((1)H NMR), (13)C NMR and infrared (IR) spectroscopy. The taxus polyprenols (TPs) had two maxima of polyprenol-17 and polyprenol-21 and different from polyprenols distributed in other plant species. A reversed-phase HPLC method with a simple gradient elution was established, and the proposed combined peak area method for the quantification of polyprenols was verified. The analysis indicated that TPs were present in the old needles at levels as high as 3% and that T. chinensis var. mairei could be an alternative botanical source for the extraction of polyprenols.