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1.
建立了用甲醛衍生测定农药比久样品中微量的偏二甲肼的方法。采用甲醛与偏二甲肼柱前衍生,在室温、中性溶液中反应10 min,生成确定量的有较强紫外吸收的偏二甲腙,不须富集可直接用HPLC法测定偏二甲肼。研究了甲醛与偏二甲肼的反应条件及产物的光谱特征,测得衍生物的最大吸收波长λmax=237 nm和表观摩尔吸光系数ε=3.6×103(L.mol-1.cm-1),选定ZorbaxODS色谱柱,V(磷酸盐缓冲溶液,pH 7)∶V(甲醇)=94∶6为流动相,检测波长为237 nm。结果表明:在0.56~960μg/mL范围内回归方程为:A=0.4677ρ-0.2790,R2=0.9998,检出限为1.3μg/g,回收率为97.5%~103.4%,相对标准偏差为0.9%~1.8%。  相似文献   

2.
建立超高效液相色谱法快速检测虾青素的方法。采用UPLC BEH C_8色谱柱(50 mm×2.1 mm,1.7μm),考察了流动相、流量及柱温对虾青素样品分离的影响,确定了最佳色谱条件:等度洗脱,流动相为甲醇–水(体积比为75∶25),流量为0.5 mL/min,柱温为40℃,检测波长为475 nm。虾青素的质量浓度在0.2~10.0μg/mL范围内与其色谱峰面积呈良好的线性关系,线性相关系数r=0.998 8,检出限(S/N=3)为0.1μg/mL,定量限(S/N=10)为0.2μg/mL。测定结果的相对标准偏差为0.41%(n=6),加标回收率为105.8%~110.3%。该方法快速、简单、可靠、灵敏、重复性好,可用于虾青素有关样品的快速检测。  相似文献   

3.
建立气相色谱–火焰光度法测定进口液化天然气中4种形态硫的方法。探讨了色谱柱、进样口温度、分流比、柱流速、升温程序和FPD检测器等对测定结果的影响。在优化的实验条件下,评价了方法的可靠性。4种形态硫化物的质量浓度在10.0~200.0μg/L范围内,其对数与峰面积对数呈良好的线性关系,线性相关系数r在0.983 3~0.999 2之间,检出限为1.7~7.7μg/L,测定结果的相对标准偏差为0.56%~0.68%(n=5)。用该法测定天然气形态硫标准气体,测定值与标准值相比,相对误差为–1.6%~–1.2%。该方法具有较高的准确度,可应用于进口天然气中4种形态硫的分析。  相似文献   

4.
建立了高效液相色谱检测蜜胺-甲醛制食品接触材料和制品中三聚氰胺特定迁移量的分析方法。采用氨基柱分离样品,乙腈和水为流动相,检测波长为214 nm。方法的检出限是0.025μg/mL,线性范围是0.05~200μg/mL(r=0.9998),回收率为87.8%~95.1%,相对标准偏差小于1%,能够满足2009年9月1日即将实施的新的国家标准GB 9690-2009《食品容器、包装材料用三聚氰胺-甲醛成型品卫生标准》对三聚氰胺特定迁移量的限量(1.0 mg/kg)要求。该方法已应用于出口蜜胺-甲醛制品中三聚氰胺特定迁移量的检测。  相似文献   

5.
采用气相色谱–质谱法测定涂料中游离氨基甲酸乙酯的含量,对样品进行超声波萃取和高速离心静化处理后,选用选择离子和保留时间定性、外标法定量,色谱柱选择RTX–WAX极性色谱柱。游离氨基甲酸乙酯的质量浓度在0.1~10.0μg/m L范围内与色谱峰面积呈良好的线性,线性相关系数为0.999 9,检出限为0.04μg/m L。加标回收率在96.8%~100.5%之间,测定结果的相对标准偏差为2.0%~11.1%(n=6)。该方法样品预处理简单、重现性好、准确度高,适用于涂料中游离氨基甲酸乙酯的检测。  相似文献   

6.
采用液相色谱/串联质谱法测定了水中的苦味酸,对流动相、流速、柱温及进样量等条件进行了优化。结果表明,流动相为甲醇和0.1%甲酸溶液(80∶20,V/V),流速1.0 mL/min,色谱柱柱温40℃,进样量5μL,苦味酸含量在1.0~50μg/L时,校准曲线呈线性关系,相关系数r=0.9999,方法检出限为0.10μg/L。对实际水样进行分析,测量的回收率为76.2%~109%,样品加标平行测定,RSD(n=6)为2.8%~4.7%。  相似文献   

7.
采用顶空-气相色谱法测定纸类产品中游离甲醛的含量。选择顶空平衡温度和时间分别为100℃和30min,用HP-INNOWAX色谱柱(60m×0.32mm,0.50μm)分离,氢火焰离子化检测器检测。甲醛的质量分数在1~100μg·g-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.4μg·g-1。以空白样品为基体进行加标回收试验,所得回收率在82.5%~94.4%之间,测定值的相对标准偏差(n=6)在2.1%~4.2%之间。  相似文献   

8.
龚淑果  梁勇  唐丽云  黄平  戴云辉 《色谱》2017,35(7):755-759
建立了丹磺酰肼(DNSH)衍生-高效液相色谱-荧光检测测定包装纸中甲醛和乙醛的分析方法,并与2,4-二硝基苯肼(DNPH)衍生法进行了比较。纸张样品经衍生化试剂振荡萃取30 min,衍生化反应24 h,萃取液经PSA/C18净化管净化处理后,以Diamonsil~ C18(2)色谱柱(150 mm×4.6 mm,5μm)为固定相,用醋酸水溶液(pH2.55)-乙腈为流动相进行梯度洗脱。采用荧光检测器检测,激发波长为330 nm,发射波长为484 nm。结果表明,衍生剂、甲醛-DNSH和乙醛-DNSH在20 min内可完全分离,方法的加标回收率为81.64%~106.78%,相对标准偏差(RSD)为2.02%~5.53%(n=5),甲醛和乙醛的检出限分别为19.2μg/kg和20.7μg/kg,定量限分别为63.9μg/kg和69.1μg/kg。该法操作简单,灵敏度高,比常规方法具有更低的检出限,能很好地应用到实际样品检测中,为低含量醛类化合物的检测提供了一种新思路。  相似文献   

9.
建立了磺胺药物残留的高效液相色谱-光化学在线衍生-荧光检测方法,并应用于猪肉的检测。样品经过乙腈提取,色谱柱分离后,通过在线光化学衍生后,用荧光检测器进行直接检测。优化后的色谱条件:Eclipse Plus C18柱(250 mm×4.6 mm,5.0μm),流动相为均含0.2%甲酸的乙腈、甲醇和水梯度洗脱,检测激发波长为248 nm,发射波长为350和412 nm。各种磺胺在各自浓度范围内线性相关系数R2>0.999,回收率在85.7%~101.1%之间,RSD为1.9%~6.6%(n=6),各磺胺的检出限(S/N=3)为0.2~3.0μg/kg,定量限(S/N=10)为0.5~10.0μg/kg。  相似文献   

10.
建立离子色谱仪同时测定卷烟主流烟气中氨和烟碱含量的方法。对样品前处理条件和色谱分离条件进行了优化,最终选择10 mmol/L盐酸作为气相捕集液和总粒相物的萃取液,在梯度淋洗条件下使用电导检测器进行测定,色谱柱为CS17阳离子分析柱,检测温度为40℃。方法学考察表明,氨和烟碱标准工作曲线线性相关系数分别为0.999 8和0.999 9,检出限分别为0.31μg/支和22μg/支。氨和烟碱测定结果的相对标准偏差分别为1.86%,2.23%(n=5),氨加标回收率在98.8%~104.9%之间,烟碱加标回收率在96.7%~103.1%之间。该方法能有效去除干扰,方法可操作性强,可同时测定卷烟主流烟气中多种成分。  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.

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   

13.
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   

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.
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   

17.
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   

18.
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   

19.
20.
黄酮化合物的合成研究进展   总被引:2,自引:0,他引:2  
黄酮化合物是一类具有多种生物活性的天然产物,其经典的合成方法主要为查耳酮路线和β-丙二酮路线.近年来出现了许多新技术、新方法.本文介绍了2'-羟基查尔酮的氧化关环法、黄烷酮氧化法、改进的Baker-Venkataraman法及其他合成黄酮化合物的方法.  相似文献   

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