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1.
提出了液体顶空-气相色谱法测定食品接触苯乙烯聚合物中残留单体及溶剂的方法。采用N,N-二甲基乙酰胺溶解聚合物,使其中残留单体及溶剂完全释放,并在优化的工作条件下,以基体匹配校正法绘制工作曲线,有效消除基质效应。7种分析物检出限(3S/N)在0.2~4.1mg.kg-1之间。测得方法的回收率在93.2%~103.2%之间,测定值的相对标准偏差(n=6)在1.1%~5.6%之间。  相似文献   

2.
洪灯  姜士磊  陈峰 《化学通报》2015,78(4):381-383
建立了使用高效液相色谱法检测塑料食品接触材料中双氰胺的分析方法.采用4%乙酸提取样品、色谱柱分离、紫外检测器检测、外标法定量测定双氰胺残留.双氰胺在质量浓度为0.1 ~5.0 mg/L范围内线性良好,相关系数为0.9996.双氰胺的最低仪器检出限为5μg/L,方法的定量下限为0.40mg/kg,样品加标的回收率在94.4% ~ 98.0%之间,相对标准偏差小于1.0%.该方法具有样品处理简单方便、灵敏度高、分析时间短等优点,可以满足塑料食品接触材料中双氰胺残留的测定,并为进出口塑料餐具中双氰胺残留量的检验提供依据.  相似文献   

3.
建立了测定烟标印刷光油中挥发性有机物(苯及苯系物、溶剂残留、溶剂杂质)的顶空-气相色谱/质谱(HS-GC/MS)联用法。将光油试样经模拟打样方式印刷在白卡纸基,加入基质校正剂三乙酸甘油酯,在干燥温度80℃与干燥时间10 min的优化条件下,选择初温40℃,速率4℃/min升温至200℃的程序升温模式,采用氦气为恒定载气流,分流比20∶1的色谱参数,经Supelco Vocol专用挥发性有机化合物(VOCs)色谱柱分离,质量分析检测器定性分析,外标法定量分析。3类挥发性组分线性关系良好,相关系数(R~2)均高于0.9965;苯及苯系物、溶剂残留、溶剂杂质检出限(LOD,S/N=3)范围分别为0.001 mg/m~2、0.004~0.210 mg/m~2、0.001~0.180 mg/m~2;定量限(LOQ,S/N=10)范围分别为0.002~0.004 mg/m~2、0.012~0.680 mg/m~2、0.003~0.520 mg/m~2;不同浓度级别下的回收率高于85.2%,其相对标准偏差(RSD,n=5)小于6.2%。该方法分析快速准确,富集效率高,具有较高的灵敏度,适用于烟标印刷光油中溶剂残留的分析检测。  相似文献   

4.
正随着社会经济的发展和物质生活水平的不断提高,人们越来越重视食品卫生和安全状况。食品包装材料直接与食品接触,其安全性关系到人体健康。复合食品包装材料是食品包装材料中种类最多、应用最广的一种软包装材料[1]。复合膜在印刷、复合、涂布等生产工序中使用了大量的有机溶剂,如甲苯、二甲苯、乙酸乙酯、丁酮等。这些溶剂或多或少地残留在复合膜中,若用含有较高残留溶剂的复合膜包装食品、药品等,将会危  相似文献   

5.
建立了QuEChERS-气相色谱/三重四极杆串联质谱(GC-MS/MS)测定杨桃中37种农药残留量的方法.样品以1%乙酸乙腈为提取溶剂,采用QuEChERS净化,在质谱多反应监测(MRM)模式下进行定性,基质匹配标准曲线外标法定量.结果表明:在0.01~0.5 mg/L范围内,37种农药的线性关系良好,方法定量限均低于0.01 mg/kg;在低、中、高3个添加水平范围内平均回收率在72.9%~117%之间,相对标准偏差(RSD)≤9.6%.该方法简单、快速、溶剂用量少、灵敏度高,适用于分析杨桃样品中37种农药残留量的检测和确证.  相似文献   

6.
郭蕾蕾  李莹  李海山  连增斌 《色谱》2018,36(12):1342-1348
建立了同时测定紫外光固化(UV)胶印油墨中27种溶剂残留(挥发性有机化合物,VOCs)的顶空-气相色谱-质谱联用(HS-GC-MS)法。将UV胶印油墨样品模拟印刷制成一定面积、厚度的试样,在紫外灯下烘烤1 min,经80℃、45 min静态顶空后,通过VOC专用毛细管柱分离和质谱检测,外标法定量。27种VOCs均呈现良好的线性关系,相关系数(R2)均≥0. 995 0;方法的检出限(LODs,S/N=3)为0. 001~0. 310 mg/m2,定量限(LOQs,S/N=10)为0. 003~0. 920 mg/m2;样品的平均加标回收率为80%~108%,相对标准偏差(RSD)6%(n=6)。该方法制样便捷,灵敏度高,精密度好,准确度高,将其应用于实际UV胶印油墨样品的检测,取得了良好效果。  相似文献   

7.
利用顶空-气相色谱串联质谱(HS-GC/MS)技术建立光油溶剂残留控制物的测定方法,对比、分析光油种类、印版清洗剂、印版线数、印刷速度、干燥温度等工艺参数对上光工序中挥发性有机物(苯及苯系物、溶剂残留、溶剂杂质)的影响及变化.经仪器参数优化,各组分相关系数(R~2)均≥0.998 2;回收率≥80.4%,相对标准偏差(RSD)5.8%(n=6).结果表明,水性光油较珠光油、UV光油溶剂残留量最少,选择纯水和正丙酯溶液结合清洗印版引入溶剂残留量最小,随印版线数增加溶剂残留量不断增大,当印刷速度达160 m/min光油附着力最佳,溶剂残留量较少,干燥温度为120℃光油表现出彻干性,溶剂得到充分挥发.  相似文献   

8.
顶空气相色谱法测定卷烟粘合剂中溶剂残留   总被引:1,自引:0,他引:1  
采用顶空气相色谱法对卷烟粘合剂中11种溶剂残留化学成分进行标准加入法检测分析。采用DB-624毛细管色谱柱(30m×0.32mm,0.25μm)分离,用火焰离子化检测器测定。在优化的柱温和顶空条件下,11种残留溶剂的测定下限(10S/N)均低于0.5μg.g-1,相对标准偏差(n=6)在1.8%~3.3%之间。甲醇、异丙醇和苯三种溶剂的回收率在94.4%~107.7%之间。  相似文献   

9.
应用HP-5毛细管柱(25 m×0.32 mm,0.25 μm)气相色谱法测定了盐酸特比萘芬药物中乙醚、异丙醇、乙酸乙酯、三氯甲烷、四氢呋喃、甲苯、二甲基甲酰胺等6种残留溶剂.经烘干的试样溶于二甲替甲酰胺(DMF)中,试样溶液中的残留溶剂经毛细管柱分离后,以苯为内标物,内标法定量测定.6种残留溶剂具有良好的分离效果,整体回收率在92.7%~101.0%之间,相对标准偏差(n=6)在1.5%~2.8%之间,6种残留溶剂检出限(S/N=3)依次为1.5,2.8,2.5,12.0,1.7,1.6 mg·L-1.  相似文献   

10.
如果油墨印刷品上残留溶剂量超过一定限度,就会使印刷品(包括印字、印花制品)相互粘结,影响质量和美观。同时,残留溶剂中的二甲苯过多,还会污染环境。而测定该残留量及分析其成分,目前还没有较好的方法。为此,我们采用气相色谱法对用油墨印刷过的塑料袋上的残留溶剂进行了定  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.
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   

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.

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   

16.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  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.
20.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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