自制苯乙烯-丙烯酸乙酯共聚物与PEG20M复合萃取涂层用于洗涤制品中1,4-二氧杂环己烷的测定

采用顶空固相微萃取-毛细管气相色谱联用技术测定了洗涤制品中的1,4-二氧杂环己烷。使用自制的萃取头（苯乙烯-丙烯酸乙酯共聚物与PEG20M复合）于顶空平衡温度80 ℃下萃取样品40 min。萃取物用内壁涂有SE-30固定液的石英毛细管柱分离,外标法定量。1,4-二氧杂环己烷含量为0.35～120 μg/g时,其峰面积与含量呈良好的线性关系（r=0.9998);回收率为98.7%～102%;相对标准偏差（n=5）为9.33%。     

气相色谱-质谱法测定地下水中多氯萘

建立了地下水中1-氯萘、2-氯萘、1,4-二氯萘、1,2,3,4-四氯萘、1,3,5,7-四氯萘、1,2,3,5,7-五氯萘、1,2,3,5,6,7-六氯萘、1,2,3,4,5,6,7-七氯萘和八氯萘9种多氯萘(PCNs)的气相色谱-质谱(GC-MS)分析方法。对比研究了液液萃取(LLE)和固相萃取(SPE)萃取地下水中PCNs的提取效率,优选二氯甲烷-液液萃取为PCNs检测的前处理方法。在优化条件下,9种PCNs的线性范围为5~100μg/L,各组分的相关系数(r)大于0.995,方法检出限(S/N=3)为4.21~7.41 ng/L,地下水的平均加标回收率为70.7%~112%,相对标准偏差(RSD,n=5)均小于9.9%。该方法已用于地下水样中多氯萘的检测。     

顶空-固相微萃取-气相色谱法检测可可麦汁中吡嗪类化合物

建立了顶空-固相微萃取(HS-SPME)-气相色谱快速测定可可麦汁中3种吡嗪类物质(2,5-二甲基吡嗪、2,3,5-三甲基吡嗪和2,3,5,6-四甲基吡嗪)的方法.选择不同的固相微萃取头对萃取温度和时间进行优化,所得最佳萃取条件为:在60℃下,采用75 μm CAR/PDMS萃取头对麦汁样品萃取40 min.本方法的检出限(S/N=3)为0.023～ 0.056 μg/L,线性范围1～500 mg/L;相对标准偏差为3.6％～6.4％;回收率为95.4％～102.7％.本方法应用于样品检测,发现可可麦汁中吡嗪的浓度与原料中可可粉的添加量正相关,显示了很好灵敏性.     

精氨酸与2,3-二氯-5,6-二氰-1,4-苯醌的荷移反应研究

用分光光度法研究了精氨酸与2,3-二氯-5,6-二氰-1,4-苯醌(DDQ)的荷移反应。实验表明,在硼砂溶液中,精氢酸与DDQ在室温下反应30min可获得稳定的络合物,其组成比为2∶1,λmax=342nm,表观摩尔吸光系数ε=1.65×104 L.mol-1.cm-1,线性范围为2～30μg/mL。应用拟定的方法测定了盐酸精氨酸注射液的含量,结果与文献方法一致,回收率在97.2%～98.1%之间,相对标准偏差小于3.1%。     

顶空气相色谱-质谱法测定洗浴用品及原材料中1,4-二氧杂环己烷残留量

提出了顶空气相色谱-质谱联用法测定洗浴用品及原材料中1,4-二氧杂环己烷残留量的方法。采用选择离子监测模式,以质荷比m/z43,58,88的特征离子进行定性分析;以质荷比m/z88的特征离子进行定量检测。1,4-二氧杂环己烷的质量浓度在500 mg.L-1以内与其峰面积呈线性关系,检出限(3S/N)为0.5 mg.kg-1。加标回收率为92.8%~105.5%,相对标准偏差(n=6)为2.50%~6.35%。     

超声萃取/气相色谱-质谱联用法对PVC制品中三(2-氯乙基)磷酸酯的快速测定

建立了PVC制品中三(2-氯乙基)磷酸酯(TCEP)的超声萃取/气相色谱-质谱联用快速测定分析方法.考察了萃取溶剂、萃取时间和水浴温度等因素对测定的影响.优化的超声萃取条件为以乙酸乙酯为萃取溶剂,萃取时间为60 min,水浴温度为40 ℃.在优化实验条件下,TCEP的质量浓度在0.1 ～10 mg/L范围内与峰面积呈良好的线性关系,相关系数为0.999 6,方法的定量下限(S/N=10)为0.1 mg/L,回收率为101% ～104%,相对标准偏差为0.76% ～3.5%.该方法具有线性范围宽、重复性好、准确度高、速度快等特点,可用于PVC制品中TCEP含量的测定.     

顶空固相微萃取-气相色谱法测定生活饮用水中痕量1,4-二氧六环

建立了生活饮用水中痕量1,4-二氧六环的顶空固相微萃取(HS/SPME)-气相色谱测定方法。考察并优化了萃取头、萃取温度、萃取时间、pH值、样品量、色谱条件等参数。结果表明:提取效率较好的方法是3 mL水样中加入3 mL 600 g/L氢氧化钠溶液,用85 μm Carboxen-PDMS萃取头萃取,用键合碱改性的大口径、厚液膜PTA-5毛细管色谱柱测定。1,4-二氧六环在0.50~50.0 μg/L范围内线性关系良好,相关系数为0.9995;方法检出限(以S/N>3计)为0.14 μg/L;相对标准偏差为2.1%~4.5% (n=6);对实际样品中进行线性范围内的高、中、低3个加标水平的测定,回收率为95.5%~107%,相对标准偏差为1.1%~5.3% (n=6)。建立的方法简便、准确、重现性好、灵敏度高,适合生活饮用水中痕量1,4-二氧六环的常规监测。     

1,2-萘醌-4-磺酸钠测定盐酸吡硫醇的研究

建立了1,2-萘醌-4-磺酸钠分光光度法测定含羟基药物盐酸吡硫醇的方法.研究表明,在pH=13.00的KCl-NaOH缓冲溶液中,盐酸吡硫醇能够催化氢氧根离子与1,2-萘醌-4-磺酸钠反应形成橙红色的2-羟基-1,4-萘醌,其最大吸收波长为454nm.盐酸吡硫醇浓度在3.2μg/mL～80μg/mL范围内与吸光度呈现良好的线性关系.线性回归方程为A＝0.02715+0.02837C(×105 mol/L),线性相关系数r＝0.9986.表观摩尔吸光系数、相对标准偏差(R.S.D.)和检测限分别为2.84×103L/mol/cm、1.6%和2.0μg/mL.通过对片剂中的盐酸吡硫醇含量进行测定,回收率在98%～101%.     

{Cd(dmt)_2(Hchdc)_2(H_2O)_2}_n配合物的合成与表征

通过水热合成的方法,以1,4-环己烷二羧酸、2,4-二氨基-6-甲基三嗪和CdCl_2·2.5H_2O为原料合成了一种单核的化合物{Cd(dmt)_2(Hchdc)_2(H_2O)_2}_n(dmt=2,4-diamino-6-methyl-triazine,H2chdc=1,4-cyclohexanedicarboxylic acid),并进行了IR和X射线单晶衍射(常温)的分析.结果表明,该化合物属于P2/c空间群,单斜晶系,晶胞参数:a=1.330 26(11)nm,b=0.541 47(4)nm,c=2.415 54(16)nm,β=115.751(3)°,V=1.567 1(2)nm~3,Z=2,Dc=1.570g/cm~3,F(000)=764,R1=0.035 2,wR2=0.092 7.该化合物中,中心金属离子Cd(II)与氧相连形成六配位构型,并通过4种不同的氢键作用最终形成了三维的堆积结构.     

食品用洗涤剂中1,4-二噁烷含量检测研究进展

对食品用洗涤剂中二(噁)烷含量的检测技术和样品前处理方法进行了概述.预见顶空-固相微萃取-气相色谱-串联四极杆技术必将对洗涤剂中的1,4-二(噁)烷含量测定起到积极作用.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.