Quality control of Metamitron in agrochemicals using Fourier transform infrared spectroscopy in the middle and near range

Two vibrational spectrometry-based methodologies were developed for Metamitron determination in pesticide formulations. Fourier transform-middle infrared (FT-MIR) procedure was based on the extraction of Metamitron by CHCl₃ and latter determination by peak area measurement between 1556 and 1533 cm⁻¹, corrected with a two points baseline established from 1572 to 1514 cm⁻¹. Fourier transform-near infrared (FT-NIR) determination was made after the extraction of Metamitron in acetonitrile and measuring the peak area between 6434 and 6394 cm⁻¹ corrected using a two points baseline defined between 6555 and 6228 cm⁻¹. Repeatability, as relative standard deviation, of 5 independent measurements at mg g⁻¹ concentration level, of 0.16% and 0.07% for MIR and NIR and a limit of detection of 0.03 and 0.004 mg g⁻¹ were obtained for MIR and NIR, respectively.NIR determination provides a sample frequency of 120 h⁻¹, higher than that found by MIR and liquid chromatographic methods (60 and 15 h⁻¹, respectively). On the other hand, the NIR method reduces the solvent consumption and waste generation, to only 1 ml acetonitrile per sample as compared with 3.4 ml chloroform required for the MIR determination and 60 ml acetonitrile used in the chromatographic reference procedure. So, vibrational procedures can be considered serious alternatives to long and time consuming chromatographic methods usually recommended for quality control of commercially available pesticide formulations.     

中红外、近红外和拉曼光谱法测定商品农药制剂中氰戊菊酯和马拉硫磷的含量

利用近红外、中红外和拉曼光谱法定量分析了商品农药制剂中有效成分氰戊菊酯和马拉硫磷的含量.采用偏最小二乘法(Partial least squares,PLS)建立氰戊菊酯和马拉硫磷的定量模型并进行了优化,用独立检验集对模型适应性进行评价.近红外和中红外法测定氰戊菊酯、马拉硫磷定量模型的相关系数分别是0.9981,0.9994和0.9946,0.9998,外部验证集标准差分别是0.082,0081和0.092,0.075,两种方法的定量效果接近;拉曼法氰戊菊酯和马拉硫磷定量模型的相关系数分别为0.9872和0.9993,外部验证集标准差分别为0.254和0.317,预测精度不及近红外和中红外法高.MIR-ATR,NIR和Raman 3种方法均能满足现场检测农药质量的需要.     

The Development of Modern Pesticides

IntroductionAt present,over80 0 different compounds areavailable for being used as pesticides[1] oragrochemicals[2 ] . Insecticides,fungicides,andherbicides constitute the largest groups but othertypes that are listed include acaricides,additives,algicides,attractants,bactericides,growthregulators,molluscicides,nematicides,repellents,rodenticides,safeners,soil sterilants,synergists,and wood protectants.The worldwide consumptionof pesticides is indicated by the level of sales in thelast decade …     

酶催化过渡态理论在药物分子设计中的应用

评述了近几年来酶催化过渡态理论在药物,包括杀虫剂,杀菌剂和解毒剂,合理分子设计中的应用进展,参考文献２９篇。     

Analytical prospect of compact disk technology in immunosensing

A sensitive and versatile methodology involving recordable compact disks as molecular screening surfaces and a standard optical CD/DVD drive as detector, is reported. Quantitative immunoanalysis, in microarray format, of a cancer marker (alpha-fetoprotein, AFP) and a selective herbicide (atrazine) on four types of audio-video disc was conducted. Enzyme or gold nanoparticle-labeled antibodies were used as tracers, forming a precipitate on the sensing disk surface. The principle of disk reading is based on capture of analog signals with the disk drive that were proportional to the darkness of the immunoreaction product. Detection limits for AFP (8.0 μg L⁻¹) and for atrazine (0.04 μg L⁻¹) were under the threshold needed to detect nonseminomatous testicular cancer, and below the maximum E.U. residue limit for drinking water, respectively. The described methodology improves the previous developments using CDs and highlights the enormous potential of immunoassay methods using standard audio–video disk surfaces in combination with the CD/DVD drive for clinical analysis, drug discovery, or high-throughput multiresidue screening applications. Figure  Eye-catching image The analytical potential of commercial audio–video discs as molecular screening surfaces in combination with use of a standard CD/DVD drive as detector for quantitative immunoanalysis of a cancer marker and agrochemical residues is demonstrated.     

几种农药的显微拉曼光谱和荧光光谱

首次用显微拉曼光谱仪测试了几种用于粮食、蔬菜、水果的农药的拉曼光谱和荧光光谱。从一些市售农药上记录到了分子振动特征峰 ,从而可以区分这些农药。此外一些市售农药的荧光光谱也很不同。据此 ,可利用拉曼光谱仪根据拉曼谱和荧光光谱的不同 ,实时实地和快速地识别这些农药及其在粮食、蔬菜、水果表面上的可能残留。     

Organotin compounds in agriculture since 1980. Part 2. Acaricidal,antifeedant, chemosterilant and insecticidal properties

The object of this review paper is to provide a guide to agrochemical research involving organotin compounds which has been performed since 1980. The information is presented in a tabular form and is divided into four main sections as indicated by the title. Each section is then subdivided to cover the various commercial organotin compounds. A final subsection lists investigations involving novel compounds. An additional section covers the effects of organotin agrochemicals on non-target organisms. A table of the contents has been provided to enable ease of reference. Acaricidal, antifeedant, chemosterilant and insecticidal properties are covered here. Fungicidal, bactericidal and herbicidal aspects are covered in Part 1.     

An uncertainty budget for the determination of the purity of glyphosate by quantitative nuclear magnetic resonance (QNMR) spectroscopy

An uncertainty budget is presented for the results of measurements of purity of the agrochemical glyphosate using ¹H and ³¹P quantitative nuclear magnetic resonance (QNMR) spectroscopy. The budget combines intralaboratory precision from repeated independent measurements of a batch, and other Type A and Type B effects. Consideration of correlation of uncertainties in ratios of mass determinations has been included. Expanded uncertainties of the purity for single determinations of purity by ¹H and ³¹P QNMR are 0.66% and 0.82% (95% confidence interval, k=2), respectively.     

近红外光谱技术快速测定农药有效成分的研究

农药有效成分含量不足和农药有效成分滥用是农药质量不合格的最主要问题,但是缺乏农药的快速现场分析方法。采用傅里叶近红外光谱技术结合偏最小二乘法(PLS),定量分析了乳油中有效成分高盖的含量,模型的决定系数R2大于0.999 9,SEC小于0.019,SEP小于0.030;同时对影响模型的因素进行了研究,并用实际样品进行了验证。结果表明：近红外光谱技术可以准确地定量分析农药乳油中有效成分含量,仪器分辨率、助剂含量变化对模型的影响不显著。近红外光谱法测量商品农药制剂中有效成分的含量,方便快速,特别适合现场、在线分析,对生产企业的连续在线检测、监督部门进行农药质量控制和农产品安全具有重要意义。