Pesticide monitoring programme of the Ministry of Health of Brazil

The structure of the recently introduced Brazilian government programme for monitoring pesticide residues in six major agricultural products is described. Residues found from the analysis of samples of tomatoes and strawberries are discussed in detail. The much greater frequency of detection of pesticide residues, many of which are not approved for use in Brazil, in produce being sold on the domestic market, as opposed to that produced for export, is of major concern. It is perceived that this new monitoring programme will become permanent and be used to underpin enforcement actions that will need to be taken to reduce the numbers of incidents of illegal residues occurring, particularly in fresh fruits and vegetables.     

Effects of home preparation on pesticide residues in cabbage

Experiment was carried out to evaluate the pesticides (chlorpyrifos, p,p-DDT, cypermethrin, chlorothalonil) residue levels in cabbage in the process of home preparation by washing with different concentrations of acetic acid and sodium chlorine, and tap water, preserving in refrigerator, and stir-frying for different time. Results showed that washing by tap water and/or detergent solution for cooking are necessary to decrease the concentration of pesticide residues in cabbage. Washing with acetic acid solutions (at 10% concentration for 20 min) caused 79.8%, 65.8%, 74.0% and 75.0% loss of the above pesticides, respectively. Washing with NaCl solutions (at 10% concentration for 20 min) produced 67.2%, 65.0%, 73.3% and 74.1% loss, respectively, and washing by tap water (for 20 min) were 17.6%, 17.1%, 19.1% and 15.2% loss, respectively. The reductions due to the refrigeration (for 48 h) were 3.4%, 2.6%, 3.1% and 3.6%, respectively, and those due to the stir-frying (for 5 min) were 86.6%, 67.5%, 84.7% and 84.8%, respectively. The data indicated that washing by detergent solutions and stir-frying of cabbage are the most effective home preparations for the elimination of pesticide residues.     

Results from the monitoring of pesticide residues in fruit and vegetables on the Danish market, 2000-01

To check compliance with the maximum residue levels in foods and to monitor the residue levels to enable an evaluation of the exposure of the Danish population to pesticides, a monitoring programme for pesticides residues in fruit and vegetables was performed. Sampling plans were designed based on previous findings and on consumption data. Samples (n = 4404) of mainly fresh conventionally and organically grown fruit and vegetables were collected at wholesalers and importers and at food processing companies. Of the samples, 3% were frozen products and 5% organically grown. Of the samples, 34% were of Danish origin, with 66% from other countries. Two accredited laboratories performed analyses of the samples using capillary gas chromatography, liquid chromatography and a spectrophotometric method. Reporting levels were set at the lowest calibration level or at the limit of determination. Residues were found in 60% of the samples of fruit but in only 18% of the vegetable samples. Residues above the maximum residue levels were found in 6% of all samples of fruit and in 2% of the vegetable samples.     

我国农药新剂型的研究进展

随着人们对保护环境的重视以及可持续发展的需要,国内外农药的剂型已朝着水基性、粒状、缓释、多功能省力化的方向发展.一些安全、经济、省力的剂型正在研究并已有应用,它们代替那些污染大,毒性高,用量大的剂型.本文对水基性剂型如水乳剂,微乳剂,悬浮剂,悬浮乳剂,微胶囊剂和干悬浮剂的特点、组成、主要产品及质量控制指标作简要的介绍,为农药新剂型研究提供参考依据.     

农药残留物的研究现状

从农药残留物的标准和检测方法等几方面介绍了农药残留物的研究现状。     

Syntheses of TiO2 photocatalysts by the molten salts method: Application to the photocatalytic degradation of Prosulfuron

Titania photocatalysts were synthesised by the molten salts method by reaction of a titanium precursor with three different alkali metal nitrates (LiNO₃, NaNO₃, KNO₃). The titania powders obtained have been characterised using TEM, XRD, BET and UV-Vis absorption spectroscopy. Their photoactivities were evaluated by degrading a commercial sulfonylurea herbicide, Prosulfuron^®. It has been found that the rate constants increased in the following order: Li2 prepared in KNO₃, with a rate constant 1.4 times smaller than that of P25. The effect of calcination was also studied, especially for the sample prepared in NaNO₃ (TiO₂[Na]). An improvement in photocatalytic activity was observed when TiO₂[Na] was calcined in the region of 700–800 °C. Even though the photocatalytic activities obtained did not exceed or even equal to that of Degussa P25, nevertheless, this study constitutes the first attempt to synthesise titania photocatalysts by the molten salts method.     

双甲脒分析方法的国际协作研究

结合参加双甲脒分析方法的国际协作研究，对国际分析方法协作研究的一般程序做了介绍，反映了国际同行们的分析水平。对国内同行了解和掌握国际协作研究的程序，及国内分析方法标准的协作实验验证也有所裨益。     

农药pH值测定方法的研究

通过对原国家标准 GB1601-79(83)农药氢离子浓度的测定方法,以及 CIPACMT75 pH 值的测定方法的研究比较,建立了一种适用于农药原药、粉剂、可湿性粉剂、乳油等的水分散液(或水溶液)pH 值测定的新方法,即新的国家标准方法。新法等效采用了 CIPAC MT75 pH 值的测定方法,使农药 pH 值的测定更加准确合理,并可在国际范围内通用。     

高纯乙酰氯生产工艺的改进

通过对国内乙酰氯现有生产工艺的考察、研究,对传统的醋酸和三氯化磷合成法进行了工艺改进,改进后工艺的产品收率比原来提高近6%,达到96.3%以上,产品质量达到99.0%以上,反应条件更加温和,操作容易控制,基本无三废产生,生产成本明显降低。     

高效液相色谱法在农药残留分析中的应用

介绍了高效液相色谱法在农药残留分析中的应用,列举了一些杀虫剂、除草剂、杀菌剂的分析方法,指出了高效液相色谱法在农药残留分析中发展方向。