强力杀虫剂氟铃脲的HPLC-MS分析

氟铃脲,通称Hexaflumuron,或XRD 473,是一种苯甲酰脲类杀虫剂,属几丁质合成抑制剂,具有强力杀虫和杀虫卵活性,高效低毒,尤其可防治棉铃虫,是一个大有前途的新农药品种,该药的化学名称为1-[3,5-二氯-4-(1,1,2,2-四氟乙氧基)苯基]-3-(2,6-二氟苯甲酰基)脲.Khoshab和Teasdale曾报道用HPLC分析土壤中的氟铃脲[1];最近Gar-rido Frenich等用HPLC-MS测定水中痕量的氟铃脲等五中苯甲酰脲农药[2].本文报道用HPLC-MS对工业氟铃脲中万分之一以上组分的鉴定,以及主成分氟铃脲的结构确证.     

强力杀虫剂氟铃脲的分析和鉴定

报道了用质谱法和高效液相色谱法对氟铃脲的分析和鉴定。１－［３，５－二氯－４－（１，１，２，２－四氟乙氧基）苯基］－３－（２，６－二氟苯甲酰基）脲，即氟铃脲，是一种能够抑制昆虫表皮几丁质合成的强力杀虫剂。由ＥＩ源质谱仪获得氟铃脲的ＭＳ图和丰度数据，并提出它的碎裂途径和特征离子。在高效液相色谱分析方法中采用ＭｉｃｒｏｐａｋＣＮ－１０柱，甲醇－水作淋洗液，检测波长２５４ｎｍ，主峰与杂质峰完全分离，用该法可分析氟铃脲粗品和制剂。     

多氟苯脲衍生物的合成研究

以三氟苯胺、对取代苯胺和固体光气为原料,基于异氰酸酯法合成了两种多氟苯脲衍生物。产品结构经IR,1H NMR,ESI-MS和元素分析表征,并对反应条件和波谱性质进行了讨论。     

溶剂替换法制备氟铃脲水悬浮剂及其分散稳定性

采用溶剂替换法制备了氟铃脲水悬浮剂,通过测定颗粒的平均粒径Dav和颗粒界面的Zeta电位,研究了分散剂种类、添加量以及有机相中乙醇的加入量对水悬浮剂分散稳定性的影响。 结果表明,在相同条件下,以苯乙烯丙烯酸共聚物(MOTAS)作为分散剂制备的水悬浮剂的分散效果较好;当MOTAS添加质量分数为1%时,Dav最小,Zeta电位绝对值最大,体系分散稳定性最好;在有机相中添加乙醇可以显著提高氟铃脲水悬浮剂的分散稳定性,当有机相中乙醇的加入质量分数增加至31.2%时分散稳定性达到最好。     

聚合物分散剂对氟铃脲水悬浮剂流变性质的影响

采用控制应力流变仪研究了聚合物分散剂苯乙烯丙烯酸无规共聚物（MOTAS）用量、分子量及氟铃脲质量分数等对氟铃脲水悬浮剂流变性质的影响。 结果表明,以聚合物MOTAS为分散剂制备的氟铃脲水悬浮剂的流变行为符合Herschel-Bulkley模型。 在固定氟铃脲质量分数为20%时,当分散剂质量分数≤3.0%时,流动行为指数n≤1.0,悬浮体系表现为假塑性流体,当分散剂质量分数≥3.5%时,流动行为指数n≥1.0,悬浮体系具有胀塑性流体特征。 氟铃脲水悬浮剂的流变参数屈服值τH与分散剂MOTAS和氟铃脲的加入量有关。 分散剂MOTAS质量分数≤2.5%时,分散剂在氟铃脲颗粒界面吸附很少,裸露的氟铃脲颗粒界面间相互搭接,具有较大的屈服值τH;当分散剂加入质量分数为3.0%时,分散剂可在氟铃脲颗粒界面形成饱和吸附,若再增加分散剂用量,多余分散剂在悬浮的氟铃脲颗粒间形成搭接,使其屈服值τH增大。 在MOTAS分散剂的分子量在10 000~30 000范围内时,MOTAS分子量愈大,所制得的氟铃脲水悬浮剂的表观粘度和屈服值τH愈小,流变行为指数n虽略有增加,但均小于1,没有改变“剪切变稀”的假塑性特征。     

新型单取代苯磺酰内脲衍生物的合成及表征

以2-氯-5-氯甲基吡啶和不同取代基的苯磺酰氯为原料, 合成了7个新型的苯磺酰内脲类衍生物, 并用FT-IR, 1H NMR, 13C NMR, 元素分析对其结构进行了表征, 同时对合成目标化合物的反应条件进行了探究.     

苯乙烯丙烯酸共聚物分散剂在氟铃脲颗粒界面的吸附性能

利用残余质量浓度法、ζ电位测定、红外光谱和XPS法系统地研究了苯乙烯丙烯酸共聚物(MOTAS)分散剂在氟铃脲颗粒界面的吸附量、吸附状态、ζ电位、吸附作用力和吸附层厚度等性能. 实验结果表明, MOTAS分散剂在氟铃脲界面的吸附符合Langmuir吸附等温式, 其饱和吸附量和吸附平衡常数k、ζ电位和吸附层厚度均随MOTAS分散剂相对分子量增加而增大, MOTAS分散剂在氟铃脲界面呈多点吸附, 氢键是分散剂分子与氟铃脲界面结合的重要作用力. 分析实验结果发现, MOTAS分散剂在氟铃脲颗粒界面吸附后具有静电排斥和空间位阻双重作用.     

高效液相色谱法测定蔬菜中除虫脲、灭幼脲和杀铃脲残留

建立高效液相色谱测定蔬菜中除虫脲、灭幼脲和杀铃脲残留的检测方法。蔬菜样品用乙腈提取,经DisQuE分散固相萃取试剂盒净化,C_(18)色谱柱(250 mm×4.6 mm,5μm)分离,以乙腈–水(68∶32)溶液洗脱,二极管阵列(PDA)检测器检测,外标法定量。在0.02~1.0 mg/L范围内,除虫脲、灭幼脲和杀铃脲的质量浓度与对应的色谱峰面积线性相关,除虫脲和灭幼脲的检出限为0.010 mg/kg,杀铃脲的检出限为0.015 mg/kg。除虫脲、灭幼脲和杀铃脲标准溶液的色谱峰面积的日内相对标准偏差分别为1.03%,1.31%,0.82%(n=6),日间相对标准偏差分别为1.43%,1.56%,1.06%(n=6)。加标回收率为88.7%~108.0%。该方法简单、快速、准确,适合蔬菜中除虫脲、灭幼脲和杀铃脲残留的测定。     

芳基吡唑缩硫代胺基脲Schiff碱的合成和表征

以苯肼或取代苯肼和硫代胺基脲为原料,通过成环、Vilsmeier反应与缩合反应合成了六种芳基吡唑缩硫代胺基脲Schiff碱,并使用FT-IR、~1H NMR对其结构进行了表征.合成方法简单,收率较好.     

2-氨基-6-三氟甲基嘧啶衍生物的合成及表征

近几年,含嘧啶结构单元的高效低毒农药层出不穷,如用作杀菌剂的嘧啶胺类、嘧啶腺类及嘧啶丙烯酸酯类,除草剂有嘧啶磺酰脲类、嘧啶水杨酸类、酰基(硫)脲类及三唑并嘧啶磺酰脲类。将含氟基团引入杂环结构是新药创制的一个发展方向,     

New Arctic Marine Sediment Certified Reference Material for Elemental Analysis

A multi-elemental certified reference material (CRM) based on Arctic marine sediment was prepared and labeled GBW 07481. Approximately 4.5?kg of the sediment was collected during the third Chinese Arctic Expedition. The sediment was processed in procedures that included air drying, debris removal, drying, and milling. The final product contained particles that were generally smaller than 74?;m representing 99% of the total mass. The powder was poured into clean 10-mL brown glass vials and a total of 300 vials were obtained. The homogeneity and stability were preliminarily investigated to assess the suitability of the marine sediment as a candidate CRM. The candidate material was demonstrated to be suitable for this purpose; and hence the certification project was accomplished with nine reputable laboratories. More than 10 reliable analytical methods, including inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), and x-ray fluorescence (XRF), were used for analyzing the sediment for 68 elements. The results should be useful for assessing the analytical accuracy of major, minor, and trace elements in marine sediments. Therefore, the CRM is expected to play an important role in Arctic geochemical surveys and environmental assessment.     

丁腈橡胶标准物质的1H-NMR表征

应用１Ｈ－ＮＭＲ技术对系列丁腈橡胶（ＢＮＲ）标准物质的结构进行了表征。测定了丁腈橡胶标准物质中聚丁二烯链段中的顺式和反式结构含量、聚丁二烯链段中１,４加成聚合与１,２加成聚合的含量以及丁腈橡胶标准物质中结合丙烯腈的含量,测定的最大相对偏差为８．３％。     

A Certified Reference Material for HPLC

A column and test samples have been produced as a Certified Reference Material (CRM) for use in HPLC. A round robin certification procedure has demonstrated that the retention and relative retention properties of the column, measured as the values of shape selectivity, hydrophobicity and ion-exchange activity at pH 7.0, under closely specified separation conditions, are reproducible irrespective of the instrument and laboratory. Concurrence with the CRM values can be used to confirm that an HPLC system is compliant with these specifications, in particular the mobile phase composition and column temperature. This will enable different laboratories to determine that they are operating under equivalent separation conditions, which is a necessary requirement for the efficient interlaboratory transferability of methods.     

小麦粉营养成分分析标准物质的研制

进行了小麦粉营养成分分析标准物质的研制。选用上海农业科学院作物研究所培育的“杨麦一号”小麦种子经脱壳、粉碎、过筛,用＾６０Ｃｏγ射线照射使其贮存稳定期达７年以上;用数理统计Ｆ检验法和ｔ检验法检验证明其均匀性良好;由９个单位共同协作定值,共定值１３７组,５４８个数据,经统计检验,小麦粉中粗蛋白质、粗淀粉、粗脂肪、氨基酸总量、天门冬氨酸、苏氨酸、丝氨酸、谷氨酸、甘氨酸、丙氨酸、缬氨酸、蛋氨酸、异亮氨酸     

甲基苯丙胺标准物质的定值与不确定度分析

为了建立法庭科学毒品检测量值溯源体系,研制了甲基苯丙胺纯度标准物质。通过红外光谱、质谱法对甲基苯丙胺样品进行定性分析,优化并建立了高效液相色谱(HPLC)、差示扫描量热法(DSC)两种定值分析方法。采用热重分析法和电感耦合等离子体质谱法测定水分和无机离子的含量。通过均匀性与稳定性检验结果表明,甲基苯丙胺标准物质的均匀性良好,稳定性至少1年,同时对其进行了不确定度评定。研制的甲基苯丙胺标准物质的纯度为99.8%,扩展不确定度为0.2%(k=2)。     

Reference materials for measuring the size of nanoparticles

This article discusses the requirements for reference materials (RMs) for measuring the size of nanoparticles (NPs). Such RMs can be used for instrument calibration, statistical quality control or interlaboratory comparisons. They can come in the form of suspensions, powders or matrix-embedded materials [i.e. NPs integrated in a natural matrix (e.g., food, soil, or sludge)].At present, uncertainty about the most suitable form of material, the most relevant measurands and the most useful metrological-traceability statement inhibits the production of NP RMs. In addition, the lack of validated methods and qualified laboratories to produce NP RMs present formidable challenges.Metal, inorganic and organic NPs are available, but most of them are intended to be laboratory chemicals. With the exception of latex materials, certified RMs are not available, although some metrology institutes have started to develop such materials for colloidal gold and silica particles.     

磷酸三(2-氯乙基)酯标准物质的研制

研制了有机磷阻燃剂磷酸三(2-氯乙基)酯(TCEP)标准物质。采用硅胶柱层析法对TCEP原料进行纯化,得到纯度大于99%的TCEP纯品。通过红外光谱和气相色谱–质谱准确定性分析后,利用气相色谱法和气相色谱–质谱法结合热重分析法分别对TCEP纯物质进行纯度定值。将制备的50 g TCEP纯品分装到100个小瓶中,每瓶0.5g,从中随机选取10瓶,进行均匀性和稳定性实验,结果表明,研制的TCEP标准物质均匀性良好,在半年内是稳定的。研制的有机磷阻燃剂磷酸三(2-氯乙基)酯标准物质的纯度定值为99.56%,扩展不确定度为1.18%(k=2)。研制的磷酸三(2-氯乙基)酯标准物质满足国家二级标准物质标准的要求。     

Certified reference material for the determination of perfluorooctane sulfonate in acrylonitrile-butadiene-styrene resin (NMIJ CRM 8155-a)

A certified reference material (CRM) for the determination of perfluorooctane sulfonate (PFOS) in acrylonitrile-butadiene-styrene (ABS) resin (NMIJ CRM 8155-a) has been issued by the National Metrology Institute of Japan (NMIJ). The bulk material was prepared by mixing commercial ABS resin powder and potassium PFOS and cut into square plates (20 × 20 mm, 2 mm thick) as the CRM. Analytical processes combined with isotope-dilution mass spectrometry and liquid chromatography/mass spectrometry were optimised and applied for characterisation. One of the approaches adopted by NMIJ for certification is that results from two or more primary methods of measurement should be used; thus, two optimised isotope-dilution mass spectrometric methods (Methods 1 and 2 with reprecipitation and with reprecipitation/solid phase extraction, respectively, were validated mutually and employed) were used to determine the certified value. Homogeneity and stability of the square plates were evaluated and their uncertainty contributions (as relative standard uncertainties) were 1.43% for inhomogeneity and 6.96% for approximately two years’ instability. The certified mass fraction of linear PFOS (heptadecafluoro-1-octanesulfonic acid) in the CRM with expanded uncertainty (coverage factor k = 2, approximately 95% confidence interval) was (33.1 ± 5.0) mg kg^?1 as free acid of PFOS.     

Certified reference material for quantification of polycyclic aromatic hydrocarbons in sediment from the National Metrology Institute of Japan

The National Metrology Institute of Japan has issued a certified reference material (CRM) of freshwater lake sediment for polycyclic aromatic hydrocarbon (PAHs) analyses. The certification used three extraction techniques: pressurized liquid extraction (PLE) with toluene, PLE with dichloromethane/ethyl acetate (1:1 by volume), and alkaline extraction (1 M KOH in methanol) in combination with microwave-assisted extraction. Both gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/dopant-assisted atmospheric pressure photoionization/MS (LC/DA-APPI/MS) analyses were used. Certified values are provided for 18 PAHs at 1–25 μg kg⁻¹ except for perylene (2.08 × 10³ μg kg⁻¹), and information values are provided for two. Since the values of PAHs in the CRM are much lower than those in other CRMs and are comparable to those found at sites with little human influence, the CRM is suitable for PAH monitoring in sediment and soil samples.     

TC11钛合金光谱分析标准物质的研制

研制了TC11钛合金光谱分析标准物质,采用合理的熔炼和锻造工艺保证了标准物质的均匀性．经方差法和极差法检验,各元素均匀性良好。采用9家权威实验室协作定值,确定的标准值准确可靠,与国内外同类标准物质比对,结果表明,该套标准物质达到了同类标准物质国际先进水平。