固相微萃取新型活性炭涂层萃取头的研究

利用合成的有机硅树脂胶粘剂和活性炭微粉首次制成活性涂层萃取头。通过苯系物(BTEX)表征了涂层表观结构、厚度及萃取性能。对苯、甲苯、乙苯、对二甲苯、邻二甲苯等进行固相微萃取,结果表明:该萃取头热稳定性好,最高使用温度可达290℃;使用寿命长,250℃解吸条件下反复使用140余次以后,膜层没有脱落或性能下降的现象。该涂层对苯系物的最低检出质量浓度在0 21～0 94μg L之间。与100μm的商品聚二甲基硅氧烷(PDMS)涂层相比,对苯系物的富集能力整体上相当。     

吹扫捕集/气相色谱－同位素比值质谱联用测定水体中痕量苯系物单体碳同位素

建立了吹扫捕集（P&T）/气相色谱－同位素比值质谱（GC/C－IRMS）联用测定水体中痕量苯系物单体碳同位素的方法。优化了吹扫时间、吹扫温度和干吹时间,确定最优吹扫捕集效率,并通过测试不同质量浓度的苯系物水溶液,计算水体中痕量苯系物的检出限。结果表明,在35 ℃下吹扫捕集13 min,干吹时间3 min条件下,水样中苯、甲苯、乙苯、间/对二甲苯、邻二甲苯、苯乙烯、异丙苯的吹扫捕集效率分别为95.0%、90.2%、71.3%、59.1%、69.4%、50.8%和70.1%,7种苯系物单体碳同位素的标准偏差（STD）为0.06‰ ~ 0.29‰。7种苯系物的质量浓度在0.50 ~ 20.00 μg/L范围内与峰面积的线性关系良好,相关系数（r2）为0.998 6 ~ 0.999 5,在各浓度下7种苯系物单体碳同位素值的标准偏差为0.090‰ ~ 0.48‰,进样量及进样方式的差异不会导致碳同位素分馏。水样中苯、甲苯、间/对二甲苯、邻二甲苯和苯乙烯的检出限为1.00 μg/L,乙苯和异丙苯为0.50 μg/L。该方法可以极大提高水体中苯系物单体碳同位素的检出限,结果准确可靠,满足水体中痕量苯系物单体碳同位素分析的需求。     

顶空固相微萃取-气相色谱-质谱联用法测定海洋沉积物中的苯系物

利用顶空固相微萃取（HS-SPME）与气相色谱-质谱（GC-MS）联用建立了测定海洋沉积物中的苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯以及苯乙烯等7种常见苯系物的检测分析方法。对无机盐的加入、平衡时间、萃取温度、萃取时间、解吸温度和时间等多个固相微萃取条件以及色谱条件进行了优化,内标法定量。结果表明：在0.500~20.0 ng/g范围内7种苯系物的线性关系良好,相关系数在0.995~0.999之间;方法检出限为0.0818~0.175 ng/g（干重）;日内和日间重现性较好,相对标准偏差分别为1.2%~3.6%（n=5）和0.4%~6.3%（n=3）;在每1.00 g海洋沉积物样品中2.0和15.0 ng加标水平下,平均加标回收率分别为61.7%~79.5%和77.1%~85.6%,相对标准偏差分别为5.4%~9.6%和3.9%~7.6%（n=5）。该方法快速、灵敏、简便,准确度高,重现性好,适合海洋沉积物样品中苯系物的痕量分析。     

有机溶剂对N，N─二乙基甲酰胺代甲基膦酸二正已酯萃取金（Ⅲ）的影响

用实验证实六种有机溶剂对Ｎ，Ｎ－二乙基甲酰胺代甲基膦酸二正已酯（Ｅ）萃取金（Ⅲ）的影响。金萃取率随下列次序下降；１，２－二氯乙烷＞环已烷＞邻二甲苯～甲苯＞四氯化碳＞氯仿。在本例中，萃取率大小与溶剂的介电常数关系不大。稀释剂是通过影响萃取剂和萃合物的分配系数或活度系数而影响金（Ⅲ）的分配比。萃合物中金（Ⅲ）与Ｅ之组成比为１∶２。     

吹扫捕集-气相色谱分析海水和沉积物中的苯、甲苯、乙苯及二甲苯

单环芳烃苯、甲苯、乙苯和二甲苯（简称BTEX）是石油的重要组分，也是环境中需要重点监测的致癌污染物。本实验建立了动态顶空（吹扫捕集）和光离子化检测器的气相色谱测量海水、沉积物中痕量BTEX的方法。在120—1200ng／L的浓度范围，苯、甲苯、乙苯、间对二甲苯及邻二甲苯标准溶液的检出限分别为6．4、35．2、15．8、12．3、10．7ng／L，相对标准偏差0．9％-6．1％。样品无需预处理，海水中BTEX回收率为93．50％-98．40％。7个渤海表层海水样品中BTEX的浓度均低于140ng／L；海底沉积物中苯、甲苯、乙苯、间对二甲苯及邻二甲苯浓度分别为169—1243、531—1732、1308—5624、237—1136、510—5194ng／L。测量方法和结果对评价环境污染具有重要意义。     

原位自组装石墨烯固相微萃取探头的制备及其在水体苯系物分析中的应用

利用石墨烯的自组装性能,原位制备了基于石墨烯材料的固相微萃取(SPME)探头,并结合气相色谱-质谱(GC-MS)建立了水体中甲苯、乙苯和邻二甲苯的分析方法。通过SEM对探头进行表征,发现制备的探头石墨烯材料均匀、牢固地结合在石英光纤上。通过优化萃取模式、萃取温度、萃取时间和盐度,得到最佳条件:顶空萃取模式、萃取温度为40℃、萃取时间为3 min、盐度为30%NaCl。在最佳条件下,3种苯系物在0.2～200μg/L范围内呈现出良好的线性,线性系数(r²)为0.998 7～0.999 6;检出限为0.001 2～0.004 2μg/L;其相对标准偏差小于5%。对采集的3个样品进行测定,均不同浓度地测出了苯系物污染,其加标回收率为90.3%～111%。该方法可用于环境水样中挥发性苯系物的分析检测。     

固相微萃取涂层的制备及其在水体和气态基质中的应用

采用物理涂渍的方法制备了γ-Al2O3固相微萃取涂层。通过γ-Al2O3固相微萃取（SPME）-气相色谱（GC）联用技术,对水中痕量苯系物苯、甲苯、乙苯、二甲苯异构体(BTEXs)进行萃取分析,结果表明该涂层具有热稳定性强(最高使用温度可达350 ℃)、灵敏度高(检测限为1~10 μg/L)以及制备重复性好（相对标准偏差为8.3%）的特点;同时该涂层对气态基质中的污染物亦可进行萃取分析。     

针式萃取-气相色谱联用测定加油站附近空气中苯系物

提出了气相色谱法测定加油站附近空气中苯系物(甲苯、乙苯、邻二甲苯和间,对二甲苯)含量的方法。采用针式萃取装置对样品中的苯系物进行收集和富集,然后经气相色谱热解吸,采用SE 30毛细管色谱柱(30m×0.25mm,0.33μm)进行分离,用氢火焰离子化检测器进行测定。方法的检出限(3S/N)在0.36～1.32μg之间。方法的回收率在94.1%～104.5%之间,相对标准偏差(n=5)在4.9%～8.7%之间。     

正己烷萃取-顶空气相色谱法测定乳胶漆中苯系物含量

应用顶空气相色谱法测定了乳胶漆中7种苯系物,即苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯及苯乙烯.作为对常规的顶空法的改进,乳胶漆中的上述7种化合物预先在顶空瓶中用n-已烷萃取,以提高方法的回收率.取1 mL气体供气相色谱分析,用HP-INNOWAX极性柱作为分离柱,并采用氢火焰离子化检测器.按保留时间值作定性分析,定量分析则采用外标法.文中给出7种化合物的线性回归方程,其相关系数在0.9989～0.9999之间,求得7种化合物的检出限(S/N=3)为0.05 ng或0.1 μg·kg-1(对0.5g试样).用此方法分析了两件乳胶漆样品,根据测得结果,算得其相对标准(n=5)值均小于5%;进行了回收试验,回收率结果苯为90%～105%,甲苯为88%～102%,乙苯为85%～102%,二甲苯为80%～98%及苯乙烯为85%～102%.     

顶空气相色谱法同时测定树脂工艺品中7种残留苯系物

建立了顶空气相色谱(HS-GC)同时测定树脂工艺品中7种残留苯系物BTEX(苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯)的方法。对溶剂种类、萃取温度、萃取时间及HG-GC分离测定条件进行优化。结果表明,在顶空温度为130℃、平衡时间为60 min、粉碎样品粒径低于2 mm、选择DB-WAX色谱柱的条件下,可获得良好的分离效果和定量结果。7种残留苯系物在0.1～500μg范围内具有良好的线性关系(r2>0.999)。方法的定量下限(LOQ,S/N=10)在0.1～0.4μg.g-1之间,加标回收率为93%～114%,相对标准偏差(RSDs,n=6)为0.7%～4.8%。所建立的方法快速、准确,适用于树脂工艺品中苯系物的测定。     

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     

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.     

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.     

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。     

Kinetics and mechanisms of chlorine dioxide and chlorite oxidations of cysteine and glutathione

Chlorine dioxide oxidation of cysteine (CSH) is investigated under pseudo-first-order conditions (with excess CSH) in buffered aqueous solutions, p[H+] 2.7-9.5 at 25.0 degrees C. The rates of chlorine dioxide decay are first order in both ClO2 and CSH concentrations and increase rapidly as the pH increases. The proposed mechanism is an electron transfer from CS- to ClO2 (1.03 x 10(8) M(-1) s(-1)) with a subsequent rapid reaction of the CS* radical and a second ClO2 to form a cysteinyl-ClO2 adduct (CSOClO). This highly reactive adduct decays via two pathways. In acidic solutions, it hydrolyzes to give CSO(2)H (sulfinic acid) and HOCl, which in turn rapidly react to form CSO3H (cysteic acid) and Cl-. As the pH increases, the (CSOClO) adduct reacts with CS- by a second pathway to form cystine (CSSC) and chlorite ion (ClO2-). The reaction stoichiometry changes from 6 ClO2:5 CSH at low pH to 2 ClO2:10 CSH at high pH. The ClO2 oxidation of glutathione anion (GS-) is also rapid with a second-order rate constant of 1.40 x 10(8) M(-1) s(-1). The reaction of ClO2 with CSSC is 7 orders of magnitude slower than the corresponding reaction with cysteinyl anion (CS-) at pH 6.7. Chlorite ion reacts with CSH; however, at p[H+] 6.7, the observed rate of this reaction is slower than the ClO2/CSH reaction by 6 orders of magnitude. Chlorite ion oxidizes CSH while being reduced to HOCl, which in turn reacts rapidly with CSH to form Cl-. The reaction products are CSSC and CSO3H with a pH-dependent distribution similar to the ClO2/CSH system.