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1.
气相色谱进样口的瞬时高温会使二苯羟乙酸-3-喹咛环酯(BZ,C21H23NO3)发生分解,经实验确定分解产物为二苯酮.温度越高,分解程度越严重.为解决此问题,采用冷柱头进样口取代传统的分流/不分流进样口,建立了新的BZ气相色谱测定方法.方法的线性范围为0.098~140.0 mg/L;相对标准偏差2.0%;检出限0.098 ng.  相似文献   

2.
建立了土壤中痕量二苯羟乙酸-3-喹咛环酯(BZ)的液相色谱-四极杆飞行时间串联质谱检测方法。BZ含量在10~400 ng/m L范围内呈良好线性关系,相关系数为0.9992,仪器定量限为5 ng/m L;在ESS-1标准土壤中的方法检出限为6.5 ng/g,在花园土中的方法检出限为6.5 ng/g;在沙土中的方法检出限为7.4 ng/g。对上述3种土壤中的BZ进行不同水平的加标回收率实验,得到方法的回收率为71%~97%,相对标准偏差(n=3)为1.3%~10%。方法已用于实际样品的检测。通过对BZ电喷雾二级质谱主要裂解途径的研究,明确了特征碎片离子的结构。  相似文献   

3.
应用气相色谱-原子发射光谱(GC-AED)同时检测S-(2-二异丙基氨乙基)甲基硫直膦酸乙酯(VX)、二苯羟乙酸-3-喹咛环酯(BZ)战剂及其降解产物等5种化合物,得取了C、H、S、N、O、P6种元素色谱图,通过选择合适的检测元素,其检出限VX为15.6mg/L,Bz为16.79mg/L,二异基氨基乙太醇为3.02mg/L,3-羟基喹咛为28.40mg/L,二苯羟乙酸甲酯为31.78mg/L,定量  相似文献   

4.
在弱酸介质中,硼、苯羟乙酸和[Fe(Phen)3]2+(phen:邻二氮菲)缔合生成具有较大疏水基团的化合物,用1,2-二氯乙烷萃取,再用去离子水反萃取,再用火焰原子吸收光谱法测定水相中铁,由此间接测定硼的含量.硼的质量浓度在0.05~3.24 mg·L-1范围内呈线性,方法检出限(3S/N)为0.036 mg·L-1.应用此方法测定了硼钢标准样品中硼含量,测得结果与已知值相符.  相似文献   

5.
气相色谱—质谱法测定水中的二苯羟乙酸   总被引:2,自引:1,他引:2  
顾惠芬  蔡冠梁 《分析化学》1994,22(8):826-828
本文报道用气相色谱-质谱法鉴定和定量测定水样中的二苯羟乙酸。对二苯羟乙酸及其甲基化产物的色谱行为进行了探讨。讨论了GC进样口污染对测定二苯羟乙酸甲酯的影响。应用本方法测定了国际实验室之间比较试验水样中的二苯羟乙酸,分析结果与HPLC方法相一致。  相似文献   

6.
用于示踪分析的固体汞合金电极线性扫描伏安法测痕量钼   总被引:2,自引:0,他引:2  
研究了可用于示踪分析测定痕量钼的固体银汞合金电极催化伏安法.在H2SO4-苯羟乙酸-氯酸钾体系中,采用该电极于-0.165V(vs.SCE)处出现灵敏的还原峰,Mo的质量浓度在0~200 ng/mL范围内与峰高呈良好线性关系,检出限为0.42 ng/mL.该方法操作简便、快速,同时又可避免传统汞电极使用中带来的不便和毒性.对实际水样进行了测定.  相似文献   

7.
徐文婷  朱若华 《分析化学》2008,36(2):201-205
以甲基丙烯酸缩水甘油酯为单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,正丙醇、1,4丁-二醇为致孔剂,制备了有机聚合整体材料膜片。合成的膜片经β-环糊精化学修饰后可同时用作固相萃取膜以及室温磷光测量的新型固体基质。考察了14种有机物在β-环糊精修饰膜片上的室温磷光行为,发现3吲-哚乙酸、1萘-乙酸、菲、7,8苯-并喹啉、咔唑和芴有较强的磷光信号,检出限为1.15~13.7 ng/spo。t实验发现,膜片可以选择性萃取和富集水样中的菲、7,8苯-并喹啉、咔唑和芴,检出限可降低至0.72~10.7μg/L。建立的方法用于水样中7,8苯-并喹啉和芴的测定,回收率分别为80.2%~111.6%和86.0%~101.7%,结果满意。  相似文献   

8.
采用新型荧光衍生试剂2-(11H-苯[a]咔唑)-乙酸(BCA)进行柱前衍生并经荧光检测对脂肪胺进行高效液相色谱(HPLC)分离和质谱定性.衍生物荧光激发和发射波长为λex=285 nm,λem=384 nm.60 ℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)作催化剂, 衍生反应15 min后获得稳定的荧光产物.在Hypersil BDS C18 (4.0 mm×200 mm, 10 μm) 色谱柱上, 采用梯度洗脱对12种脂肪胺衍生物进行了优化分离.采用大气压化学电离源(APCI Source)正离子模式进行质谱定性, 实现了各种脂肪胺衍生物的快速、准确测定.脂肪胺的线性回归系数不小于0.999 8 , 检出限(S/N=3)为5.73 ~31.3 fmol.  相似文献   

9.
建立了在线液相-气相二维色谱测定卷烟主流烟气中的苯并[a]芘方法.采用剑桥滤片捕集烟气粒相物,环己烷萃取,以D12-苯并[a]芘为内标,然后用在线液相-气相二维色谱测定:样品直接进样进入液相色谱,经微型硅胶柱分离,含苯并[a]芘的部位切割进人气相色谱,排干溶剂后启动气相色谱升温,经毛细管柱进行分离,用质谱检测.本方法将烟气苯并[a]芘测定中的硅胶柱层析和气相色谱-质谱分析在线连接起来,可不经样品前处理净化直接进样分析;而且每次进样可达40 μL,与常规气相色谱-质谱分析最大进样2.0 μ.L相比,分析灵敏度提高了20倍.方法线性范围达0.08~ 50 ng/L,相关系数为r2=0.999,回收率为94.2%~105.5%;检出限和定量限分别为0.09和0.30 ng/支,应用本方法对14个不同类型市售卷烟和2R4F标准烟进行了测定,结果与GB/T21130-2007测定结果相符合.  相似文献   

10.
对化学毒剂及其降解产物的分析检测是准确鉴别化学沾染的重要手段.由于化学毒剂及其降解产物的样品可能存在于各种基质中,且部分化学毒剂在水体等基质中降解速度过快,所以将痕量样品从复杂基质中快速高效的富集提取出来显得尤其重要.微萃取技术具有装置体积小、使用少量或不使用溶剂、绿色环保、易与色谱分析技术联用等突出优势受到广泛的关注...  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
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。  相似文献   

12.
13.
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。  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.

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.

  相似文献   

18.
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。  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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