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1.
采用顶空毛细管气相色谱法测定吡虫啉中的丁酮残留量。样品经二氯甲烷溶解,用HP–5毛细管色谱柱分离,氢火焰离子化检测器检测,顶空平衡温度为70℃,平衡时间为10 min,以外标法计算含量。丁酮的质量浓度在2.0~510.0μg/m L范围内线性关系良好,相关系数r=0.999 7,方法的检出限为0.5μg/m L,样品3个水平的加标回收率为99.4%~102.1%,测定结果的相对标准偏差小于3.0%(n=5)。该方法简便快速,准确可靠,可用于吡虫啉产品的质量控制。  相似文献   

2.
建立吹扫捕集–气相色谱–质谱联用法测定地表水中硝基苯的方法。用吹扫捕集法对水样进行前处理,以HP–5弱极性毛细管柱(30 m×0.32 mm,0.25μm)进行分离,质谱法测定水中硝基苯的含量。硝基苯的质量浓度在0.00~60.0μg/L范围内与色谱峰面积线性关系良好,线性相关系数为0.999 4,方法的检出限为0.03μg/L。测定结果的相对标准偏差小于2%(n=7),地表水样品加标回收率在91.2%~96.5%之间。该方法操作简便,检出限低,精密度和准确度高,适用于地表水中硝基苯的测定。  相似文献   

3.
建立了气相色谱-质谱联用测定化妆品中苯酚和氢醌的检测方法.用甲醇作为提取试样,经HP-INNOWAX毛细管色谱柱分离,选择特征离子监测扫描模式(SIM)测定.结果表明:苯酚的方法线性范围为0.01~50μg/m L(r=0.999 96),检出限为0.05μg/g,加标回收率为91.3%~99.6%,相对标准偏差为1.5%~6.0%.氢醌的方法线性范围为0.02~50μg/m L(r=0.999 87),检出限为0.10μg/g,加标回收率为91.5%~99.7%,相对标准偏差为3.2%~5.5%.方法简单、快速、灵敏,可有效消除化妆品基质的干扰,适用于化妆品中苯酚和氢醌的定性、定量测定.  相似文献   

4.
建立一种快速检测PM2.5中阴离子和有机酸的离子色谱方法。以Thermo Fisher Ion Pac AS18–4μm为分析柱,AG18–4μm为保护柱,以氢氧化钾溶液为流动相,等度洗脱,5 min内进行分离。被测组分的质量浓度与色谱峰面积具有良好的线性,相关系数在0.998 5~0.999 9之间,各色谱峰面积的精密度在0.98%~1.9%(n=7)之间,各组分加标回收率为92.1%~107.4%,检出限为0.04~2.00μg/L。该方法可应用于评价区域大气的质量。  相似文献   

5.
建立了同时测定血浆、红细胞、尿液中硫胺素(T)、一磷酸硫胺素(TMP)、二磷酸硫胺素(TDP)的柱前衍生/反相高效液相色谱-荧光检测法。样品经高氯酸除蛋白,铁氰化钾衍生后,采用反相色谱柱分离,荧光检测器测定,外标法定量。色谱柱为C18柱(250 mm×4.6 mm,5μm i.d.),流动相为0.2 mol/L KH2PO4溶液(pH 7.0,含0.000 3 mol/L四丁基氢氧化铵)-甲醇和甲醇-水,采用梯度程序进行洗脱,流速为0.8mL/min。荧光检测器激发波长为365 nm,发射波长为435 nm。结果表明:T,TMP在0.5~20.0μg/L,TDP在5.0~200.0μg/L质量浓度范围内呈良好的线性关系,相关系数分别为0.99,0.98,0.99。T,TMP,TDP的平均回收率为86.8%~110.2%,相对标准偏差(RSDs)为2.5%~10.9%。3种化合物在血浆及红细胞中的检出限(LODs)为0.03~0.35μg/L,定量下限(LOQs)为0.09~1.18μg/L。T在尿液中的检出限(LODs)为1.58μg/L,定量下限(LOQs)为5.26μg/L。该方法的准确度和精密度均较高,能够满足临床检测和科研需要。  相似文献   

6.
研究了二维离子色谱测定海水中铵离子的方法。海水样品经10倍稀释,一维色谱采用高容量的CS–165 mm柱,以30 mmol/L甲磺酸溶液等度淋洗,流量为1 m L/min,进样25μL,CSRS–300 4 mm抑制电导分离Na+,NH4+;二维色谱采用CS–12A 4 mm柱,以8 mmol/L甲磺酸溶液等度淋洗,流量为1 m L/min,以1 300μL定量环进样,SC–CSRS–300盐转换器抑制电导检测NH4+。结果表明:色谱峰面积与NH4+质量浓度线性相关,相关系数为0.999 9。10μg/L标准溶液测定结果的相对标准偏差为2.7%(n=7),NH4+的方法检出限和仪器检出限分别为0.42,0.05μg/L,海水中NH4+加标回收率为80.8%~105.8%。  相似文献   

7.
建立了高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)测定化妆品中2-溴-2-硝基-1,3-丙二醇的方法。采用ZORBAX RX-C_8色谱柱(150×2.1 mm,5μm)进行分离,以甲醇-水-5%磷酸(10∶985∶5,用2 mol/L NaOH调至pH 3.0)为流动相,流速为0.7 m L/min,柱温为室温。结果显示,2-溴-2-硝基-1,3-丙二醇在2.5 min处出峰,其线性范围为0.01~1.0 mg/L,相关系数为0.999 9。不同基质化妆品的方法检出限均为1.0μg/g,回收率为94.6%~101.3%,相对标准偏差(RSD,n=6)为1.5%~4.5%。该方法快速、准确、灵敏、无干扰,适用于化妆品中2-溴-2-硝基-1,3-丙二醇的定性定量测定。  相似文献   

8.
建立作业场所空气中1-丁烯和1,3-丁二烯的直接进样气相色谱测定方法。利用TEDLAR气袋采集空气样品,以VARIAN–PLOT大口径毛细管柱分离,六通阀进样,FID检测器检测。1-丁烯,1,3-丁二烯的线性范围分别为23.3~466 mg/m3,11.3~225 mg/m3,检出限(3S/N)分别为0.08,0.03 mg/m3,相关系数均大于0.999。测定结果的相对标准偏差为0.8%~3.1%(n=6),回收率在92.0%~104.3%之间。该方法简便、快速、准确,灵敏度高,适用于作业场所空气中1-丁烯和1,3-丁二烯的检测。  相似文献   

9.
建立高效液相色谱法测定制何首乌配方颗粒中2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷含量的方法。采用Therm O ODS–2 HYPERSIL(250 mm×4.6 mm,5μm)色谱柱分离,以乙腈–水(20∶80)为流动相,流量为1m L/min,柱温为40℃,在320 nm处检测。2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷的质量浓度在5.736~86.040μg/m L范围内与其色谱峰面积具有良好的线性关系,线性相关系数r2=0.999 96,检出限为1.310μg/m L。回收率为99.4%~103.1%,测定结果的相对标准偏差为0.16%~1.35%(n=6)。该法操作简便,准确度高,重现性好,可作为制何首乌配方颗粒质量控制方法之一。  相似文献   

10.
建立了三氟乙酸( TFA)柱前衍生,加压毛细管电色谱-激光诱导荧光( pCEC-LIF)快速测定黄曲霉毒素B1、B2、G1、G2方法。使用粒径1.8μm的C18毛细管色谱柱,以甲醇-水(45:55, V/V,含0.05%甲酸)为流动相,泵流速为0.05 mL/min,分离电压为15 kV,激发波长为375 nm,发射波长为450 nm,黄曲霉毒素B1, B2, G1, G2达到基线分离。各组分的检出限(S/N=3)分别为0.02,0.016,0.008和0.01μg/L,在0.1~10μg/L,0.1~10μg/L,0.1~3.0μg/L,0.1~3.0μg/L 范围内分别呈线性相关,相关系数 R2分别为0.9999,1.0000,0.9995,0.9997。将本方法应用于花生酱的分析,加标回收率在90.0%~112.0%之间,RSD在0.5%~1.9%之间。  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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