凝固-漂浮分散液液微萃取-高效液相色谱法测定水样中氯酚

采用凝固-漂浮分散液液微萃取(SFO-DLLME)-高效液相色谱法测定水样中3种氯酚.以密度小于水,且凝固点为24 ℃的1-十二醇为萃取剂,甲醇为分散剂,对水样进行分散液液微萃取.将混合液离心,再通过冷冻凝固操作使漂浮的萃取剂和水相分离,萃取剂复溶后进样测定.本实验确定的最佳实验条件为:萃取剂200 μL、分散剂300 μL、1.2 g NaCl、1 mol/L H3PO4 200 μL、样品体积8.0 mL、萃取时间3 min.3种氯酚测定的线性范围为0.05～6.0 mg/L;检出限为20～38 μg/L.应用本方法分析实际水样,加标回收率在90.11%～107.7%之间;日间相对标准偏差在3.5%～4.6%之间.本方法扩展了分散液液微萃取萃取剂的选择范围,具有简便、快速、准确、环境友好等特点.     

基于轻质萃取剂的溶剂去乳化分散液-液微萃取-气相色谱法测定水样中多环芳烃

以密度小于水的轻质溶剂为萃取剂,建立了无需离心步骤的溶剂去乳化分散液-液微萃取-气相色谱(SD-DLLME-GC)测定水样中多环芳烃的新方法。传统分散液-液微萃取技术一般采用密度大于水的有机溶剂为萃取剂,并需要通过离心步骤促进分相。而本方法以密度比水小的轻质溶剂甲苯为萃取剂,将其与丙酮(分散剂)混合并快速注入水样,获得雾化体系;然后注入乙腈作为去乳化剂,破坏该雾化体系,无需离心,溶液立即澄清、分相;取上层有机相(甲苯)进行GC分析。考察了萃取剂、分散剂、去乳化剂的种类及其体积等因素对萃取率的影响。以40 μL甲苯为萃取剂,500 μL丙酮为分散剂,800 μL乙腈为去乳化剂,方法在20～500 μg/L范围内呈现出良好的线性(r2=0.9942～0.9999),多环芳烃的检出限(S/N=3)为0.52～5.11 μg/L。用所建立的方法平行测定5份质量浓度为40 μg/L的多环芳烃标准水样,其含量的相对标准偏差为2.2%～13.6%。本法已成功用于实际水样中多环芳烃的分析,并测得其加标回收率为80.2%～115.1%。     

分散液液微萃取-高效液相色谱串联质谱法快速测定水迁移相中甲醛

建立了分散液液微萃取-高效液相色谱串联质谱法快速测定轻纺消费品水迁移相中痕量甲醛的分析方法。水迁移相甲醛首先与2,4-二硝基苯肼(2,4-DNPH)衍生化反应生成甲醛-2,4-二硝基苯腙,优化的反应时间为15 min,2,4-DNPH浓度为5 mmol/L,HCl浓度为50 mmol/L;在分散液液微萃取过程中,以500μL乙腈为分散剂、50μL四氯乙烯为萃取剂瞬间完成衍生物的萃取富集后,进行HPLC-ESI-MS/MS分析,分析时间为3.5 min。水相中甲醛的检测线性范围为0.001~1 mg/L,线性相关系数(R2)为0.9987,检出限为0.25μg/L。平均加标回收率范围在82.8%~113.5%,相对标准偏差范围在2.1%~9.2%,平均富集倍数为120。方法已经应用于轻纺消费品水迁移相中甲醛含量的测定。     

中空纤维碳纳米管/正辛醇固-液协同微萃取机理及其应用

讨论了以中空纤维为载体的碳纳米管/正辛醇固-液协同微萃取机理,建立了中空纤维碳纳米管/正辛醇固-液协同微萃取-高效液相色谱法同时测定复杂样品中微量咖啡酸、阿魏酸和肉桂酸含量的方法.以2.5 cm长的聚偏氟乙烯中空纤维为碳纳米管正辛醇分散液载体,供相为分析物的HCl(pH 2.1)溶液,接受相为pH 12.7的NaOH溶液,在35℃下,搅拌萃取60 min,萃取液进行高效液相色谱紫外检测.在优化的实验条件下,分析物的线性范围均在0.05～50 μg/L,r＞0.9990 (n=5);检出限均为0.015μg/L;日内与日间精密度均小于9.8％(n=9),平均回收率为93.8％～115.2％;富集倍数分别为514,942和1084倍.在以中空纤维为支持体的碳纳米管/正辛醇微萃取中,碳纳米管/正辛醇分散液嵌入中空纤维管壁上的微孔中形成了碳纳米管/正辛醇固-液微萃取单元束,对苯丙烯酸类化合物起到协同萃取作用.     

分散液液微萃取-气相色谱法测定水样中甲拌磷农药

建立了基于分散液液微萃取(DLLME)的新型样品前处理方法,并采用气相色谱/氢火焰离子化检测器对水样中痕量的甲拌磷农药进行了测定。考察了影响分散液液微萃取的因素包括萃取溶剂、分散剂、样品体积、萃取温度和离心速度等。在最佳实验条件下,对甲拌磷的富集倍数达到300倍;检出限为0.001μL/L;方法的线性范围为0.01~10μL/L,R2为0.9986;相对标准偏差为6.65%;回收率为104%。将分散液液微萃取法与单滴液相微萃取和离子液体-液相微萃取方法进行了对比,结果表明,分散液液微萃取技术具有操作简单、快捷(前处理时间小于5 min)、富集效果好、回收率高等优点。同时预言,将离子液体与分散液液微萃取结合,将会产生更加满意的结果。     

气相色谱火焰光度法测定水体中9种有机磷酸酯阻燃剂

建立了水体中9种有机磷酸酯阻燃剂(OPFRs)的液液萃取(LLE)/气相色谱-火焰光度(GC-FPD)测定方法。对比研究了液液萃取、固相萃取条件和仪器测定条件。最终选择液液萃取作为样品的提取方法,以二氯甲烷为提取溶剂;有机磷专用柱Rtx-OPPesticides 2作为分析柱,15 min内可实现待测组分的良好分离。在优化条件下,9种OPFRs在1.0~500 ng/m L范围内呈良好的线性关系(r2≥0.998),方法检出限为1.0~2.0 ng/L。在5,100,300 ng/L加标水平下,9种OPFRs空白水样的加标回收率为75.9%~111%;相对标准偏差(RSD)为3.3%~15%。该方法应用于6个实际湖泊地表水样品的检测,OPFRs的检出率为100%,其组分检出总浓度为408~1 532 ng/L,可见湖泊地表水中存在明显的OPFRs污染。     

凝固-漂浮分散液液微萃取-HPLC法测定环境水样中单取代萘类化合物

采用凝固-漂浮分散液液微萃取(SFO-DLLME)技术联用高效液相色谱(HPLC)(二极管阵列检测器)法检测环境水样中的2-甲基萘、1-氯萘和1-溴萘。以低成本的正癸醇(密度:0.8287 g/cm3;凝固点:6℃)作为凝固-漂浮分散液液微萃取的萃取剂,讨论了分散剂类型和体积、萃取剂体积、萃取时间、离心时间和盐效应等因素对SFO-DLLME萃取效率的影响。在最优化条件下,2-甲基萘、1-氯萘和1-溴萘的检出限分别为0.09,0.10,0.24 ng/m L,线性范围为0.4~300 ng/m L,相对标准偏差(n=5)为1.5%~4.6%,对以上目标分析物的加标回收率为94.4%~106.2%。方法已应用于检测自来水和湖水中的2-甲基萘、1-氯萘和1-溴萘。     

微流控液液萃取-液液波导集成化分析系统

利用溴化1-丁基-3-甲基咪唑离子液体/碳酸钠溶液双水相体系,实现了多相层流液液萃取.以具有较高折射率的离子液体为液芯,较低折射率的盐溶液为包层,实现了液液波导吸光度检测.据此建立了一种液液萃取与液液波导检测集成化的微流控分析系统.该系统对甲酚红试样的萃取率在93%以上,对甲酚红试样检测的线性范围为0.01~0.40 mg/m L,相对标准偏差为3.4%(n=11),检出限为3.8μg/m L(3σ).该系统将萃取分离与液液波导长光程吸光度检测集成在一起,为拓展吸光度检测在微流控系统中的应用提供了新思路.     

液-液-液微萃取-高效液相色谱法测定人血浆中的局部麻醉剂

建立了液-液-液微萃取与高效液相色谱联用技术同时测定人血浆中3种局部麻醉剂利多卡因、布比卡因和丁卡因的方法。考察了萃取时间、料液pH值和搅拌速度的影响,取佳萃取条件为萃取溶剂为200μL苯,接受相为1.0μL 0.2 mol/L HC l,搅拌速度为250 r/m in,萃取时间为45 m in。在该条件下,获得了高的富集因子(大于305倍)。方法的线性范围为:利多卡因和布比卡因0.025~5 mg/L,丁卡因0.05~5 mg/L,相关系数大于0.996;检出限依次为0.005、0.015和0.025 mg/L;相对标准偏差小于5%。该方法能有效地去除血浆中复杂基体的干扰,萃取效率高,有机溶剂消耗少,是一种有效、灵敏的同时测定血浆中利多卡因、布比卡因和丁卡因的方法。     

分散液液微萃取-反相液液微萃取-扫集-胶束电动色谱法测定红酒中的3种氯酚类物质

建立了分散液液微萃取（DLLME）-反相液液微萃取（RP-LLME）-扫集-胶束电动色谱富集模型,并用于红酒中五氯酚（PCP）、2,4,6-三氯酚（TCP）和2,4-二氯酚（DCP）3种氯酚的测定。实验考察了两步微萃取的萃取参数对氯酚萃取率的影响和样品分离富集的电泳条件。最佳萃取条件DLLME为：3.5 mL红酒（pH 3.0,120 g/L NaCl）,300 μL正己烷（萃取剂）;RP-LLME为：25 μL 0.16 mol/L NaOH（萃取剂）。最佳电泳条件：25 mmol/L NaH₂PO₄,100 mmol/L十二烷基硫酸钠（SDS）,30%（v/v）乙腈,pH 2.3;分离电压-15 kV;样品基质为80 mmol/L NaH₂PO₄;压力进样20 s×20.67 kPa（3 psi）。PCP和TCP的线性范围为0.5~100 μg/L（r≥0.9910）,DCP的线性范围为1.5~80 μg/L（r=0.9851）。3种分析物的检出限（S/N=3）为0.035~0.114 μg/L,加标回收率为75.2%~104.7%,相对标准偏差≤6.17%。该方法富集倍数高、灵敏度高、重现性好、分析速度快,可为不同样品基质中痕量氯酚污染物及某些弱酸性有机污染物测定提供参考。     

Nucleophilic Substitution in 1,5-Benzodiazepin-2-ones

The reaction of 3-bromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one with cyclic amines gives 3-aminoalkyl-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one. Thiazolo[4,5-b][1,5]benzodiazepine was isolated along with the substitution product when thiourea was used.     

Special features of the alkylation of 7-bromo-5-(2-chlorophenyl)- 3-hydroxy-1,2-dihydro-3h-1,4-benzo- diazepin-2-one with alkyl tosylates

On interacting 7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one with methyl, hexyl, dodecyl, and cetyl tosylates, 1-alkyl-7-bromo-5-(2-chlorophenyl)-1,2,4,5-tetrahydro-3H-1,4-benzodiazepin-2,3-diones, and 1-alkyl-7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin- 2-ones were obtained. Only the dione was formed in the case of hexyl tosylate. On alkylating with methyl tosylate only the 3-hydroxy derivative was formed. It was shown that at pH 14 the 1-cetyl and 1-dodecyl-3-hydroxy derivatives were completely converted into the corresponding diones. The molecular and crystal structures of the compounds were established by X-ray structural analysis.     

Microbiological synthesis of 7-bromo-5-(o-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one by immobilized actinomycetes

It has been shown that the highest yields (15%) of 7-bromo-5-(o-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one are obtained by the use of the cells of actinomycetes immobilized in poly(vinyl alcohol) in the presence of the cosubstrate 7-bromo-5-(o-chlorophenyl)-3-methyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one.     

Determination of midazolam and its major hydroxy metabolite in plasma by gas liquid chromatography. Application to a pharmacokinetic study

A sensitive gas liquid chromatographic (GLC) assay was developed for plasma determinations of 8-chloro-6-(2′ -fluorophenyl)-1-methyl-4H-imidazo[1,5 α][1,4]benzodiazepine (compound I) and its hydroxymethylimidazo metabolite (compound II). The internal standards used were 8-chloro-6-(2′ -chlorophenyl)-1 -methyl-4H-imidazo[1,5 α][1,4]benzodiazepine (compound VI) and 7-chloro-5-(2′ -fluorophenyl)-1, 3-dihydro-1-(hydroxyethyl)-2H-1,4-benzodiazepin-2-one (compound VII) for compounds I and II, respectively. Following extraction, and silylation for compound II, compounds I and II were analyzed by GLC using a glass column packed with 5% OV-101 on Gas-Chrom Q, and a ⁶³Ni electron-capture detector. The GLC method was validated by a CI-GC/MS technique. The detection limit of the assay is approximately 4–5 ng/ml for compound I and 3 ng/ml for compound II. The method was used in comparative pharmacokinetic studies of the distribution of the two compounds in arterial and venous blood.     

Synthesis and structure of 3-arylidene and 3-hetarylidene-1,2-dihydro-3H-1,4-benzodiazepin-2-ones and their affinity toward CNS benzodiazepine receptors

The condensation of 5-aryl-7-bromo-1,2-dihydro-3H-1,4-benzodiazepin-2-ones with aromatic aldehydes gives 5-aryl-3-arylidene-and 5-aryl-7-bromo-3-hetarylidene-1,2-dihydro-3H-1,4-benzodiazepin-2-ones. X-ray diffraction structural analysis yielded the molecular and crystal structures of 7-bromo-3-(4′-methoxybenzylidene)-5-phenyl-1,2-dihydro-3H-1,4-diazepin-2-one and showed that this compound has cis configuration. Radioligand analysis was used to study the affinity of these products toward central nervous system and peripheral benzodiazepine receptors. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1213–1225, August, 2007.     

A NOVEL SERIES OF PALLADIUM(II) AND PLATINUM(II) COMPLEXES WITH 1,4-BENZODIAZEPINES AS LIGANDS

Abstract

The complexing behaviour towards palladium(II) and platinum(II) halides of some 1,4-benzodiazepines is reported. The ligands used in this study are 7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepin-4-oxide, 1,3-dihydro-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one and 7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one. The complexes have been studied by means of magnetic susceptibility measurements, infrared and far infrared spectra, electronic spectra and conductivity measurements. The most convincing structural evidence for these complexes is a square planar stereochemistry with bridging ligands joining two metal ions and terminal halides in the 1:1 complexes and terminal ligands and terminal halides in the 1:2 derivatives. Assignments for the metal-ligand and metal-halide bands have also been made.     

Microbiological synthesis of 7-bromo-5-(o-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one by immobilized actinomycetes

It has been shown that the highest yields (15%) of 7-bromo-5-(o-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one are obtained by the use of the cells of actinomycetes immobilized in poly(vinyl alcohol) in the presence of the cosubstrate 7-bromo-5-(o-chlorophenyl)-3-methyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one.Physicochemical Institute, Academy of Sciences of the Ukrainian SSR, Odessa. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 779–783, November–December, 1981.     

Peculiarities of inclusion complex formation in the 1,4-benzodiazepine-benzene system

5-Phenyl-1-methyl-7-bromo-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one and its 5-(o-chloro)-phenyl analog form 2:1 (host:guest) inclusion compounds with benzene. The crystal structures of the compounds were studied by the single-crystal XRD method and were interpreted as host (H) (benzodiazepine) — guest (G) (benzene solvent molecule) complexes. The studied structures, revealing H-H and H-G interactions as both typical hydrogen bonds and π-π, C-H?π weak interactions, may serve as models for ligand-receptor binding.     

Curtius rearrangement in the 5-phenyl-1,4-benzodiazepine series. Unprecedented participation by an imine nitrogen

The previously unknown 3-aminomethyl-1,3-dihydro-5-(2′-fluorophenyl)-2H,4-benzodiazepin-2-one, 3a, was synthesized in two steps as a racemate. In the chiral series, 3(S)-azidocarbonylmethyl-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one, 12b, was prepared from Nα-Cbz-β-methylaspartate in five synthetic operations and subjected to Curtius rearrangement. The intermediate isocyanate was trapped intramolecularly by the 5-imine nitrogen of the benzodiazepine ring in 12b. This unanticipated result runs counter to the generally held dictum that the isocyanate group has a strictly linear shape.     

Synthesis and crystalline and molecular structure of hydrochloride of 1-[2(2,3-dihydro-1,3,4-oxadiazolyl-5-one)]methyl-7-bromo-5-prenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one

By the interaction of 1-hydrazinocarbonylinethyl-7-bromo-5-phenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one with phosgene, the compound 1-[2(2,3-dihydro-1, 3,4-oxadiazolyl-5-one)jmethyl-7-bromo-5-phenyl-1, 2-dihydro-3H-1, 4-benzodiazepin-2-one has been synthesized. Spectroscopic methods and x-ray structure analysis have been used to establish the crystalline and molecular structure of this new derivative of 1, 4-benzodiazepine.A. V. Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine, Odessa 270080. Institute of Applied Chemistry, Academy of Sciences of the Republic of Moldova, Kishinev 277028. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 689–693, May, 1995. Original article submitted March 17, 1995.