液相色谱串联质谱法测定果蔬中的唑虫酰胺、氟啶虫酰胺、氯虫苯甲酰胺及氟虫双酰胺残留

建立了同时测定蔬菜和水果中唑虫酰胺、氟啶虫酰胺、氯虫苯甲酰胺和氟虫双酰胺残留量的液相色谱-串联质谱(LC-MS/MS)分析方法。样品经乙腈提取,过滤后进行盐析,上层有机相经QuEChERS方法净化浓缩后,用乙腈-水(体积比20∶80)定容进行分析。采用XBridgeTMC18色谱柱,以0.1%甲酸溶液-乙腈体系进行梯度洗脱,MRM方式测定,基质外标法定量。在优化条件下,唑虫酰胺和氟啶虫酰胺的线性范围为0.075~2.0 mg.L-1,氯虫苯甲酰胺和氟虫双酰胺为0.015~0.40 mg.L-1,线性相关系数均不低于0.998。唑虫酰胺、氟啶虫酰胺、氯虫苯甲酰胺及氟虫双酰胺在蔬菜和水果样品中的检出限(S/N=3)为0.000 8、0.005、0.002、0.000 5 mg.kg-1。蔬菜和水果中4种农药在0.05~5.0 mg.kg-1(氟啶虫酰胺和唑虫酰胺)和0.01~1.0 mg.kg-1(氟虫双酰胺和氯虫苯甲酰胺)加标范围内的回收率为80%~95%,批内RSD为2.0%~6.1%,批间RSD为3.3%~7.6%。     

高效液相色谱-串联质谱法测定蔬菜中氯虫苯甲酰胺和氟虫双酰胺残留

建立了蔬菜中氯虫苯甲酰胺和氟虫双酰胺残留量的高效液相色谱-串联质谱同时分析方法.蔬菜样品加入乙腈高速匀浆,提取液中加入无水MgSO4和NaCl,振荡离心后,取上清液稀释后直接进样,液相色谱-串联质谱电喷雾正离子扫描同时分析氯虫苯甲酰胺和氟虫双酰胺.以甘蓝、白菜、黄瓜、辣椒、番茄和茭白6种蔬菜为基质进行4个添加水平和5次重复性实验,结果表明, 添加浓度为0.01～5 mg/kg,蔬菜中氯虫苯甲酰胺和氟虫双酰胺添加回收率为85.4%～105%,相对标准偏差(RSD, n=5) 为2.5%～12%,氯虫苯甲酰胺和氟虫双酰胺的方法检出限(LOD)分别为0.0003 和0.002 mg/kg,定量限(LOQ)分别为0.001和0.006 mg/kg.本方法操作简单,灵敏度、回收率和重复性均良好.     

液相色谱-串联质谱法测定果蔬中双三氟虫脲、四氯虫酰胺和氰虫酰胺残留

建立了蔬菜和水果中双三氟虫脲、四氯虫酰胺和氰虫酰胺3种新型杀虫剂的分散固相萃取-液相色谱-串联质谱检测方法.样品经乙腈均质提取,混合使用乙二胺-N-丙基硅烷(PSA)和C18基质分散净化剂进行净化,液相色谱-三重四极杆串联质谱(LC-MS/MS)同时进行检测.双三氟虫脲和四氯虫酰胺采用多反应监测负离子模式,氰虫酰胺采用多反应监测正离子模式.双三氟虫脲在苹果、洋葱和经微波处理的洋葱样品中均不存在基质效应,可采用纯溶剂标准外标法或者采用基质匹配标准溶液定量检测; 四氯虫酰胺和氰虫酰胺存在程度不同的基质减弱效应,采用空白基质匹配的校正标准曲线外标法定量.3种杀虫剂均在0.2～100 μg/L线性范围内具有良好的线性关系,相关系数均大于0.9990.在0.005～2.000 mg/kg范围内,平均添加回收率为81.6％～99.9％,相对标准偏差为3.6％～9.8％.氰虫酰胺、四氯虫酰胺和双三氟虫脲的检出限分别为0.064,0.048和0.001 μg/kg,定量限分别为0.210, 0.160和0.004 μg/kg.     

高效液相色谱法检测噻虫嗪-氟虫腈悬浮剂

采用高效液相色谱法测定农药复合制荆120 g/L噻虫嗪-60 g/L氟虫腈悬浮荆.采用ODS C18反相色谱柱(150 mm×4. 6 mm i. d. ,5μm),乙腈一水(体积比为4∶6)为流动相,用紫外检测器在240 nm波长下,对试样中的噻虫嗪和氟虫腈进行分离和定量检测.噻虫嗪、氟虫腈的平均回收率分别为99. 0%～102. 0%、96. 0%～104. 0%,测定结果的相对标准偏差分别为0. 5%、1. 6%(n=6).     

荔枝与龙眼中噻虫啉、螺虫乙酯及代谢物的高效液相色谱-串联质谱分析

采用高效液相色谱-串联三重四极杆质谱结合QuEChERS前处理技术,建立了同时测定荔枝和龙眼中噻虫啉、螺虫乙酯及4种代谢物残留的分析方法。样品采用乙腈作为提取溶剂,经十八烷基键合硅胶(C18)与石墨化碳黑(GCB)吸附剂净化后,由Poroshell-120 EC-C18色谱柱分离,以0. 1%(体积分数)甲酸水溶液-乙腈为流动相等度洗脱,在电喷雾电离(ESI+)和多反应监测模式下进行检测,外标法定量分析。该方法的线性范围为1～500μg/L,相关系数(r~2)均大于0. 990,检出限(LOD)为0. 03～0. 3μg/kg,定量下限(LOQ)为0. 1～1. 5μg/kg。荔枝和龙眼中噻虫啉、螺虫乙酯及4种代谢物在1、10、100μg/kg加标水平下的平均回收率为80. 4%～99. 5%,相对标准偏差(RSD)为1. 4%～6. 4%。该方法操作简单、灵敏度高、准确性好、可靠性强,可满足荔枝和龙眼等水果中噻虫啉、螺虫乙酯及代谢物的快速筛查监测要求。     

QuEChERS结合超高效液相色谱-串联质谱法同时测定番茄中噻虫嗪、噻虫胺、螺虫乙酯及其代谢物残留

建立了QuEChERS-UPLC-MS/MS法快速同时检测番茄中噻虫嗪及其代谢产物(噻虫胺)、螺虫乙酯及其4种代谢产物(BYI08330-enol-glucoside、BYI08330-mono-hydroxy、BYI08330-enol和BYI08330-ketohydroxy)残留的分析方法。样品经乙腈提取,NaCl和无水Mg SO4除水后,经N-丙基乙二胺(PSA)和C18粉末净化,用超高效液相色谱-串联质谱(UPLC-MS/MS)分析,采用多反应离子监测模式(MRM)检测,基质匹配标准溶液外标法定量。7种目标物质在0.2~2 000μg/L质量浓度范围内均具有良好的线性关系(r2≥0.999 2),在0.002、0.02、0.20、2.00 mg/kg加标水平下的平均回收率为79.9%~104%,相对标准偏差(RSD)为0.94%~6.4%,方法定量下限(LOQ)为0.002 mg/kg。该方法快速简便、灵敏度高、重现性好,能满足番茄中噻虫嗪、噻虫胺和螺虫乙酯及其代谢产物残留的快速检测和确证要求。     

气相色谱-电子轰击源质谱法测定茶叶中氟虫腈残留量

建立了茶叶中氟虫腈残留量快速测定的气相色谱-电子轰击源质谱法。茶叶中的氟虫腈用正己烷-丙酮(7:3,V/V)混合液提取,经石墨化碳黑固相萃取小柱净化后,用正己烷-丙酮(9:1,V/V)混合液洗脱,浓缩定容后,用气相色谱-电子轰击源质谱法测定,外标法定量。结果表明,目标物质在0.001~0.040 mg/L范围内的线性关系良好;空白样品在0.002~0.010 mg/L范围三水平加标回收实验的平均回收率在96.6%~114.2%之间,相对标准偏差(n=6)为2.9%~4.4%;方法的定量限为0.001 mg/kg。该方法能满足茶叶中氟虫腈残留量0.002 mg/kg的检测要求。     

分散固相萃取/液相色谱-串联质谱法测定花生及土壤中的噻虫啉

建立了一种检测土壤、花生植株、花生果实及花生壳中噻虫啉的分散固相萃取(DSPE)/液相色谱-串联质谱(HPLC-MS/MS)快速检测方法。对提取溶剂、不同分散固相吸附剂及其用量进行了考察和优化。样品经0.1%乙酸乙腈溶液提取后,以50 mg N-丙基乙二胺吸附剂(PSA)、50 mg十八烷基键合硅胶(C18)和10 mg石墨化碳黑(GCB)固相萃取填料净化,采用水-甲醇作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,质谱采用多离子监测模式(MRM)进行定性分析,基质标准曲线外标法进行定量分析。在0.1~50μg/kg范围内,不同基质中噻虫啉的线性相关系数均大于0.996。在土壤、花生植株、花生果实及花生壳中添加3个不同浓度水平的噻虫啉标准品,得到噻虫啉的回收率为70.6%~119%,相对标准偏差不大于16.6%,方法的定量下限为1.0~5.0μg/kg,能够满足现有国际限量的要求。     

气相色谱–质谱法测定鲜蛋中氟虫腈及其代谢物

建立鲜蛋中氟虫腈及其代谢物氟甲腈、氟虫腈砜、氟虫腈亚砜残留量的气相色谱–质谱检测方法。样品采用乙腈提取,用QuECHERS萃取包和氨基固相萃取柱净化,外标法定量。氟虫腈、氟甲腈、氟虫腈砜、氟虫腈亚砜的质量浓度在0.01～0.20μg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数均在0.999以上,方法检出限为0.002 mg/kg。样品的加标回收率为90.8%～104.5%,测定结果的相对标准偏差小于10%(n=6)。该方法具有较好的灵敏度、准确性和重复性,适用于鲜蛋中氟虫腈及其代谢物氟甲腈、氟虫腈砜、氟虫腈亚砜残留量的测定。     

QuEChERS净化GC/ECD测定茶叶与土壤中噻虫嗪、虫螨腈及高效氯氟氰菊酯残留

采用QuEChERS方法净化,建立了GC/ECD法同时检测茶叶和土壤中噻虫嗪、虫螨腈和高效氯氟氰菊酯残留的分析方法。样品经水浸润后,乙腈提取,适量PSA、GCB和Florisil混合填料净化提取液,GC/ECD检测。噻虫嗪、虫螨腈和高效氯氟氰菊酯的响应分别在0.50～400、0.20～100、0.40～200μg/L质量浓度范围内线性良好,相关系数r均大于0.99,检出限分别为0.25、0.05、0.10μg/L。茶叶和土壤样品中,噻虫嗪、虫螨腈和高效氯氟氰菊酯的平均加标回收率为62%～108%,相对标准偏差(RSDs)不大于15.8%,方法的定量下限(LOQs)均不大于10μg/kg。方法简便、快速,能够满足茶叶和土壤中上述3种不同极性农药残留同时检测的需要。采用该方法测定了3种农药在茶园茶叶和土壤中的残留量,结果满意。     

Synthesis and structure of hydroxyisoxazolidines and derivatives of hydroxylamine and alkenals

The reactions of N-substituted hydroxylamines with alkenals serve as a method for the synthesis of the corresponding 2-substituted 3(5)-hydroxyisoxazolidines. The reaction pathway is determined by the nature of the substituent attached to the nitrogen atom. Ring-chain isomerism has been detected in these newly obtained compoundsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1270–1276, September, 1987.     

Synthesis and characterization of triazenide and triazene complexes of ruthenium and osmium

Triazenide [M(eta2-1,3-ArNNNAr)P4]BPh4 [M = Ru, Os; Ar = Ph, p-tolyl; P = P(OMe)3, P(OEt)3, PPh(OEt)2] complexes were prepared by allowing triflate [M(kappa2-OTf)P4]OTf species to react first with 1,3-ArN=NN(H)Ar triazene and then with an excess of triethylamine. Alternatively, ruthenium triazenide [Ru(eta2-1,3-ArNNNAr)P4]BPh4 derivatives were obtained by reacting hydride [RuH(eta2-H2)P4]+ and RuH(kappa1-OTf)P4 compounds with 1,3-diaryltriazene. The complexes were characterized by spectroscopy and X-ray crystallography of the [Ru(eta2-1,3-PhNNNPh){P(OEt)3}4]BPh4 derivative. Hydride triazene [OsH(eta1-1,3-ArN=NN(H)Ar)P4]BPh4 [P = P(OEt)3, PPh(OEt)2; Ar = Ph, p-tolyl] and [RuH{eta1-1,3-p-tolyl-N=NN(H)-p-tolyl}{PPh(OEt)2}4]BPh4 derivatives were prepared by allowing kappa1-triflate MH(kappa1-OTf)P4 to react with 1,3-diaryltriazene. The [Os(kappa1-OTf){eta1-1,3-PhN=NN(H)Ph}{P(OEt)3}4]BPh4 intermediate was also obtained. Variable-temperature NMR studies were carried out using 15N-labeled triazene complexes prepared from the 1,3-Ph15N=N15N(H)Ph ligand. Osmium dihydrogen [OsH(eta2-H2)P4]BPh4 complexes [P = P(OEt)3, PPh(OEt)2] react with 1,3-ArN=NN(H)Ar triazene to give the hydride-diazene [OsH(ArN=NH)P4]BPh4 derivatives. The X-ray crystal structure determination of the [OsH(PhN=NH){PPh(OEt)2}4]BPh4 complex is reported. A reaction path to explain the formation of the diazene complexes is also reported.     

Mass and NMR spectra of haplophyllidine and perforine and of their derivatives

Conclusions The mass and NMR spectra of haplophyllidine, perforine, and their derivatives have been studied. The influence of the open and cyclic forms of the molecular ion on the nature of the fragmentation has been discussed. The main routes of fragmentation of the compounds considered are due to the presence of substituents at C₈ and C₄.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 273–279, 1969     

Crystal and molecular structure of aroyl- and acetylhydrazones of acet- and benzaldehydes

Aroyl- and acetylhydrazones of acet- (I) and benzaldehydes (IV) and benzoylhydrazones of acet- (II) and benzaldehydes (III) were studied by x-ray structural and quantum-chemical methods in order to establish their structures. Compund (I) was the EEZ structure in the crystal. Calculations and spectral data showed that the EEE form occurs in nonpolar solvents and in the gas phase. According to crystallographic data molecules (I)–(IV) are the E-isomers (relative to the N-N bond) and the hydrazone fragments are planar. Intermolecular N-H...O H-bonds from in the crystals. The data obtained suggest that the majority of acylhydrazones are conformationally rigid on dissolution although exceptions do occur. Apparently the reasons for the difference of acetyl- and benzoylhydrazones in electrocarboxylation reactions are electronic and not steric factors.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 75–81, January, 1991.     

Investigation of adhesion and mobility of polyurethane and epoxy-rubber glues and adhesives

The values of activation parameters in uncured and cured epoxy resins, rubbers, and blends thereof are investigated. The dependences of activation energy and adhesion strength of epoxy-rubber compositions on rubber content are determined. The correlation of adhesion and activation energy values for polyurethane rubber and epoxy-rubber compositions is shown.     

Preparation and characterization of diarylphosphazene and diarylphosphinohydrazide complexes of titanium, tungsten and ruthenium and phosphorylketimido complexes of rhenium

Reaction of the proligand Ph2PN(SiMe3)2 (L1) with WCl6 gives the oligomeric phosphazene complex [WCl4(NPPh2)]n, 1 and subsequent reaction with PMe2Ph or NBu4Cl gives [WCl4(NPPh2)(PMe2Ph)] (2) or [WCl5(NPPh2)][NBu4] (3), respectively. DF calculations on [WCl5(NPPh2)][NBu4] show a W=N double bond (1.756 A) and a P-N bond distance of 1.701 A, which combined with the geometry about the P atom suggests, there is no P-N multiple bonding. Reaction of L1 with [ReOX3(PPh3)2] in MeCN (X = Cl or Br) gives [ReX2(NC(CH3)P(O)Ph2)(MeCN)(PPh3)](X = Cl, 4, X = Br, 5) which contains the new phosphorylketimido ligand. It is bound to the rhenium centre with a virtually linear Re-N-C arrangement (Re-N-C angle = 176.6 degrees, when X = Cl) and there is multiple bonding between Re and N (Re-N = 1.809(7) A when X = Cl). The proligand Ph2PNHNMe2(L2H) reacts with [(C5H5)TiCl3] to give [(C5H5)TiCl2(Me2NNPPh2)] (6). An X-ray crystal structure of the complex shows the ligand (L2) is bound by both nitrogen atoms. Reaction of the proligands Ph2PNHNR2[R2 = Me2 (L2H), -(CH2CH2)2NCH3 (L3H), (CH2CH2)2CH2 (L4H)] with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave [RuCl2(eta6-p-MeC6H4iPr)L] {L = L2H (7), L3H (8), L4H (9)}. The X-ray crystal structures of 7-9 confirmed that the phosphinohydrazine ligand is neutral and bound via the phosphorus only. Reaction of complexes 7-9 with AgBF4 resulted in chloride ion abstraction and the formation of the cationic species [RuCl(6-p-MeC6H4iPr)(L)]+ BF4- {(L = L2H (10), L3H (11), L4H (12)}. Finally, reaction of complex 6 with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave the binuclear species [(eta6-p-MeC6H4iPr)Cl2Ru(mu2,eta3-Ph2PNNMe2)TiCl2(C5H5)], 13.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。