气质联用仪测定水果中的甲基异柳磷农药残留

建立了水果中甲基异柳磷农药残留的气相色谱-质谱仪检测方法。水果样品用乙腈匀浆提取,盐析离心后,取上清液,经固相萃取柱净化,用乙腈-甲苯溶液(3+1)洗脱农药及相关化学品,溶剂交换后用安捷伦7890B-7000D气质联用仪检测。结果表明,空白样品加标回收率范围为88.6%～112.8%,相对标准偏差小于10%,甲基异柳磷的检出限为0.001 mg/kg。该方法操作简便、准确、灵敏、重现性强、回收率高、基质干扰少,适用于农药残留量的测定。     

中草药与苯扎溴铵联用治疗车轮虫病的案例分析

车轮虫病是鱼类重要的常见纤毛虫病。近年来,对传统化学药物耐药的车轮虫和小车轮虫越来越多。本文介绍了复方中草药联合苯扎溴铵治疗河鲀、黄颡鱼和草鱼车轮虫病的典型案例,以期为类似病例治疗提供参考。     

EMS和60^Co-γ射线辐照复合诱变黄麻突变体苗期生理生化特性研究

为丰富黄麻种质资源和扩大突变体容量,本研究采用物理诱变（60^Co-γ）和化学诱变（EMS）相结合的方法,以＂中黄麻4号＂等7个黄麻品种为材料,观察记录诱变黄麻苗期的形态学变化,分析诱变黄麻的代谢特性和抗性指标。结果表明EMS和60^Co-γ射线对黄麻幼苗的叶片产生不同程度的损伤,前者主要导致叶片卷曲,后者导致叶片分叉。复合诱变导致黄麻幼苗脯氨酸含量、丙二醛含量和根系活力提高。而可溶性蛋白、SOD活性和POD活性变化则品种之间呈现差异。本研究为黄麻种质创新的方法提供了参考,并且丰富了黄麻突变体的材料。     

泡沫消毒剂在养殖场的临床应用研究

为考察泡沫消毒剂对鸡场的消毒效果,选取洛阳周边一家蛋鸡场进行试验。将戊二醛苯扎漠鞍溶液按1 : 100倍稀释,使用自吸式泡沫清洗一体机进行消毒,分别考察泡沫消毒后30 min对地面、墙面和料槽的消毒效果,结果表明,使用泡沫型消毒剂戊二醛苯扎漠钱溶液以1 : 100倍稀释消毒30 min后,消毒效果在99.93%以上,消毒效果良好,这种泡沫消毒方法值得临床推广应用。     

芦笋茎枯病菌对甲基托布津的抗药性初步研究

经检测江苏芦笋主产区丰县和赣榆芦笋茎枯病菌对甲基托布津已发生严重抗药性。丰县和赣榆田间抗性菌株比例为６８．２％和８８．９％,存在低抗（５＜ＥＣ５０≤２０μｇ／ｍＬ）、中抗（２０＜ＥＣ５０≤１００μｇ／ｍＬ）和高抗（ＥＣ５０＞１００μｇ／ｍＬ）突变体。抗药菌株在不含药的培养基中经单孢分离连续培养８代,抗性仍保持稳定。高抗菌株对噻菌灵、苯菌灵、多菌灵表现正交互抗性,对乙霉威表现敏感;低抗、中抗菌株对乙霉威不敏感。抗药菌株的产孢力、菌丝生长速率与敏感菌株相近。     

木材辐射接枝甲基丙烯酸甲酯的效果

用 γ射线辐照研究了五种木材辐射接枝甲基丙烯酸甲酯的效果,以及３ 种辐照方式和辐射剂量对接枝增重率的影响⒚结果表明：五种木材的接枝增重率分别处在 ２３．６％ ～１６６．５％ 范围内, 其中杉木的接枝增重效果最好⒚辐照方式和辐射剂量对接枝增重效果有一定影响,浸水辐照有助于提高接枝增重率,辐射剂量与接枝增重率呈正相关⒚     

原子吸收分光光度法测定人发痕量镉的研究

以硝酸—高氯酸为消化液,消解人发试样,采用碘化钾—甲基异丁酮萃取发样中的镉,采用原子吸收分光光度法,将有机相喷雾测定。并且对直接法、标准加入法和原子吸收分光光度法进行了比较。本测定方法 C? V小于 3.1%,标准加入回收率在 95.6%～103.2%之间,结果可靠,适用于人发中痕量镉的测定。     

The persistence of methyl bromide residues in rice,dried fruit,seeds and nuts following laboratory fumigation

The persistence of methyl bromide (MB) in white rice, brown rice, sultanas, raisins, pumpkin seeds, brazil nuts, groundnuts and walnuts was monitored following laboratory fumigations at different concentration time products and temperatures. A sensitive automated headspace gas chromatographic method with a limit of quantitation of 0.005 mg kg⁻¹ was used to determine MB residues. Nuts and seeds sorbed the highest amounts of MB followed by rice and dried fruit. Measurable MB residues were shown to persist in nuts and seeds for 10 weeks and in dried fruit for four weeks following a fumigation with recommended concentration time products. The data presented suggest MB residues may persist in unprocessed nuts, seeds or dried fruit at the point of consumption using recommended fumigation practices, or particularly following overdosing or multiple fumigations. Crown copyright © 2000 Reproduced with the permission of Her Majesty's Stationery Office     

Applicability of ELISA for determination of metsulfuron‐methyl in soil samples

An immunoassay (ELISA) for analysis of metsulfuron‐methyl was evaluated as a method for quantifying residues in soil. Soil samples were extracted with phosphate buffered saline (PBS), PBS + acetone (80 + 20 by volume) or ammonium carbonate and were analyzed with both ELISA and LC‐MS. A tendency for the ELISA to overstimate the metsulfuron‐methyl content was noted and matrix effects were pronounced, particularly in PBS + acetone or ammonium carbonate extracts. Dilution of extracts before analysis improved the situation but reduced the sensitivity of the assay. Using light standard concentrations it was shown that the extracts in PBS on dilutions exhibited a curve parallel with the standard curve, indicating no significant interference due to matrix effects. A working range of 10–250 ng litre⁻¹ was found for ELISA on this type of extracts. © 2000 Society of Chemical Industry     

菜籽油脱臭馏出物中生物柴油的分子蒸馏分离工艺研究

为了实现脱臭馏出物的清洁加工,运用分子蒸馏技术分离菜籽油脱臭馏出物中合成的生物柴油,考察了分子蒸馏的操作参数对生物柴油回收率的影响,研究结果表明：当系统压力为5.3 Pa,蒸发面温度120℃,进料温度70℃,刮膜转速150 r/min,进料速率120 mL/h时,生物柴油回收率达到41 g/100 mL。馏出物经高分辨气相色谱-质谱进行分离鉴定,共检出6种脂肪酸甲酯成分：其中棕榈酸甲酯33.61%,油酸甲酯16.14%,亚油酸甲酯18.25%,硬脂酸甲酯8.81%,芥酸甲酯7.39%,贡多酸甲酯3.78%,脂肪酸甲酯总含量占89%以上。