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1.
环境和生物样品中多来宝残留量的气相色谱分析方法研究   总被引:3,自引:0,他引:3  
龚道新  杨仁斌  郭正元  沈丹 《色谱》1996,14(6):481-483
 湿性样品中的多来宝残留物用丙酮(水样和干样用石油醚)提取,提取液经石油醚再萃取、浓缩后,用被石油醚饱和的乙腈分配,过硅胶氧化铝混合柱净化,室温下与(CH3)3SiI衍生化反应,生成3-苯氧基苄基碘,用GC检测。当添加浓度为0.05,0.10,1.00μg/g时,样品的平均回收率为80.7%~110.0%,方法最小检出量为0.01ng,样品最小检出浓度是:水0.001mg/L,稻米和土壤0.01μg/g,稻草、谷壳、水浮莲和罗非鱼为0.008μg/g。  相似文献   

2.
用反相高效液相色谱法追踪分析不同时间内羊血清中药物浓度的变化,以供药物代谢动力学研究。药物为丙硫咪唑砜和丙硫咪唑亚砜(简称砜和亚砜),实验条件为ODS柱,流动相甲醇:水=7:3(v/v),紫外检测波长为290nm。在3h左右测定浓度达峰值,其最高浓度分别为4.01μg/mL和11.47μg/mL,五天左右下降为2.73μg/mL和1.32μg/mL附近。最小检出量为0.4ng/mL及0.7ng/mL。线性关系良好。丙硫咪唑砜和亚砜的回归相关系数分别为0.9994和0.9991。采用内标法测定回收率,平均为100±12%。  相似文献   

3.
焙烧富集分离—氢化物原子荧光法测定地质物料中痕量硒   总被引:2,自引:1,他引:2  
任萍  张勤 《分析试验室》1994,13(4):65-67
本文研究了一种焙烧富集分离,氢化物-原子荧光法测定地质物料中痕量Se方法。系统地了Se富集分离条件,考查了30多种元素在焙烧前后对测定Se的影响。在选定的最佳实验条件下,方法检出下限为0.01μg/g和0.089μg/g,线性范围0.001-0.3μg/mL。样品中Se含量水平为0.036μg/g和0.089μg/g时的测量精度(RSD)分别为10%和5.8%。加标回收率为97-99%。采用本方法  相似文献   

4.
活性氧化铝富集火焰原子吸收法测定铬(Ⅲ)和铬(Ⅵ)   总被引:5,自引:0,他引:5  
研究了内装活性氧化铝的微型柱流动注射富集分离火焰原子吸收光谱法(Fl-FAAS)测定水体中μg/L级的Cr(Ⅲ)、Cr(Ⅵ)。用0.2mol/L氨水将活性氧化铝转为碱式以吸附Cr(Ⅲ),1mol/L硝酸洗脱;用0.01mol/L的硝酸将活性氧化铝转为酸式以吸附Cr(Ⅵ),0.2mol/L的氨水洗脱,洗脱液直接送到喷雾器中。进样30s,浓度富集25倍。两种价态离子的校正曲线浓度范围在1~50μg/L之间,检测限分别为0.6和0.7μg/L,样品分析速率为60样/h。研究了共存离子的干扰情况,实际水样中的加标回收率在85%~105%之间。  相似文献   

5.
焙烧富集分离-氢化物原子荧光法测定地质物料中痕量硒   总被引:5,自引:0,他引:5  
本文研究了一种焙烧富集分离、氢化物-原子荧光法测定地质物料中痕量Se的方法。系统地研究了Se富集分离条件、考查了30多种元素在焙烧前后对测定Se的影响,在选定的最佳实验条件下,方法检出下限为0.01μg/g,线性范围为0.001~0.3μg/mL。样品中Se含量水平为0.036μg/g和0.089μg/g时的测量精度(RSD)分别为10%和5.8%。加标回收率为97~99%。采用本方法分析了26个地球化学标准参考样中痕量硒,获得满意结果。  相似文献   

6.
火焰原子吸收法测定植物样品中硼与碘   总被引:13,自引:0,他引:13  
龙斯华  刘秋林 《分析化学》1995,23(4):430-433
将BO^3-3转化为BF^-4,IO^-3转化为I^-以Cd(phen)^2+3络合和硝基苯萃取,用火焰原子吸收法间接测定与碘,其特征浓度达0.016μg/mL1%A和0.028μg/mL1%A,在稻米等样品中作加标回收,硼回收率为92.8-102.4%,碘为97.2-106.7%。  相似文献   

7.
本文报告了在0.01mol/LCTAB体系中,以F-为掩蔽剂、苯芴酮显色、用分光光度法测定饮料食品中Ge-132含量,最低检测限0.054μg/mL;线性范围0.54~27.14μg/mL;回收率96.3%~101.5%,并确定了Ge-132摩尔吸收系数(ε)3.39×104。用本法测定了康寿茶、矿泉水和博士奶中Ge-132含量,灵敏度高、重现性和准确度好。用盐酸化本体系,研究了二氧化锗(Ge~(4+))的含量测定,其最低检测限0.021μg/mL;线性范围1.0~21.0μg/ml;回收率95.8%~102.8%,Ge-132不干扰。饮料食品中同时存在Ge-132和Ge(4+)时,本体系可分别测定两者含量。  相似文献   

8.
不经分离,高敏,连续光度滴定混合物中钕和铁   总被引:3,自引:0,他引:3  
提出以Fe(3+)(Nd(3+)-CAS-CPB-C2H5OH作为不经分离、高敏、连续光度配合滴定混合物中Fe(3+)和Nd(3+)的多元胶束配合指示体系。滴定Fe(3+)和Nd(3+)的适宜pH分别为2.3~3.2和6.0~8.6。用EDTA目视滴定Fe(3+)时,终点处由蓝紫变粉红色,对比度大(Δλ=130nm)、灵敏度高(配合物摩尔吸光系数ε(630)=1.14×105L·cm(-1)·mol(-1),至少可检测0.4μg/mL,滴定线性范围为0~2.8μg/mL。线性相关系数为0.9994;目视滴定Nd(3+)时,终点处由绿色变橙黄,Δλ>180nm,ε(630)=7.6×104,至少可检测1μg/mL,滴定线性范围0~3.7μg/mL,线性相关系数0.9994。对于铁钕硼混合物样品则不经分离在630nm处连续光度滴定,可更精密、高敏、准确地确定终点,变异系数1.76%~2.86%,标准加入回收率96%~104%,且简便、快速。  相似文献   

9.
流动注射—化学发光分析测定矿石中痕量铌   总被引:5,自引:0,他引:5  
利用铌对鲁米诺-H2O2-K3Fe(CN)6化学发光体系的抑制作用,建立了痕量Nb(Ⅴ)的流动注射-化学发光测定法。方法的检出限是2.3ng/mLNb(V).线性范围为0.01-1μg/mlNb(V),测定的相对标准偏差为3.0%(0.01μg/mLNb(V)(n=11),方法已应用于矿石中Nb的测定。  相似文献   

10.
24种安眠镇静药物的气相色谱及气相色谱-质谱系统分析   总被引:1,自引:0,他引:1  
建立了24种安眠镇静药物的气相色谱(GC)及气相色谱-质谱(GC-MS)系统分离分析方法。该法在选定的色谱条件下,能将24种安眠镇静药物很好地分离,互不干扰。采用内标法定量,其线性范围在0~24μg/mL血,最小检出浓度为0.1~0.4μg/mL血。用所建的GC方法对11例中毒病人的生物样品进行分析鉴定,GC-MS法验证。从实际中证明所建方法操作简便,准确性和系统性强,灵敏度较高,能快速、准确地为医院的救治提供依据。  相似文献   

11.
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   

12.
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   

13.

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   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

16.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

19.
袁丽秋 《化学教育》2006,27(5):8-10
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。  相似文献   

20.
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