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用乙醇对草酰氯进行柱前衍生化,通过气相色谱法测定草酰氯的含量。以苯甲酸乙酯为内标物,OV-225毛细管柱分离,氢火焰离子化检测器检测。在选定的色谱条件下,衍生物、内标物及杂质能得到有效分离,并能获得较好的检测效果。分析结果表明,草酰氯的线性相关系数为0.999 8,回收率为99.1%~100.9%,变异系数为0.52%。 相似文献
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<正> 对苯二甲酰氯(TPC)是聚对苯二甲酰对苯二胺(芳纶1414)和聚砜酰胺的单体,它是由对苯二酸(TPA)经酰卤化反应制取的。TPC 中杂质的种类和含量与原料TPA 中杂质、TPC 合成情况及纯化方法有关。主要是相应原料酸中杂质酸的酰氯,根据TPA 合成路线的不同,主要有苯甲酰氯(BC)、对甲基苯甲酰氯(PTC)、邻苯二甲酰氯(PC)和间苯二甲酰氯(IPC)等。另外,合成TPC 时,反应不完全或水解产生的对苯二甲酸单酰氯(TPMC)和TPA、氯化氢及合成中产生的其它杂质等等。单酰氯的存在会封闭分子链,得不到高分子量的聚合物,而异构体会影响高聚物链结构。因此,建立TPC 中杂质测定方法对其合成、纯化和稳定地制取高分子量聚合物具有重要意义。酰氯是具有高度反应性的化合物,在空气或色谱 相似文献
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异丙胺基磺酰氯为除草剂灭草松的一个重要中间体。该酰氯中间体与某些酰氯化合物的稳定度不同,其氯原子特别活泼,若遇湿或雨天时,即逐渐地水解。因此,给制备、样品纯化和保存及其含量测定都带来困难。由于原油中存在其它有机物质,并伴有氯化亚砜和分解的二氧化硫及无机氯等,故不能采用一般的化学分析法。本文提出简便分配层析——银盐滴定法。此法,以无水石油醚分离主要干扰物质,然后用0.05N银盐标准溶液进行滴定,计算其含量。 相似文献
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I. I. Domsky M. B. Graber M. M. Goldstein 《Journal of the American Oil Chemists' Society》1972,49(1):84-85
A colorimetric method has been developed, suitable for determining low levels (10–200 ppm) of phosphorous in detergent formulations
containing large amounts of silicate. Samples are ashed to remove organic matter, hydrolyzed to convert all phosphates to
ortho-phosphate, and centrifuged to remove any SiO2, carbon or other solids. Phosphomolybdic acid is formed and extracted into an organic solvent, where it is reduced to the
classic molybdenum blue color by stannous chloride. The procedure yields accurate and reproducible results, with reliability
at the 25 ppm phosphorous level of ±3 ppm. 相似文献
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A facile method was developed to quantify unreacted ketene acetals during polymerization of poly(ortho ester)s. The method was based on isotopic (deuterium) labeling of the unreacted ketene acetal groups arising from the diketene acetal monomer, 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5,5]undecane (DETOSU). In deuterium oxide, free ketene acetals are hydrolyzed to an α-deuterated ester; ortho ester bonds are hydrolyzed to the nondeuterated analog. The relative abundance of the deuterated ester side chain can be quantified by gas chromatography-mass spectrometry (GC-MS). In the current method, aliquots of a diketene acetal/polyol(s) reaction mixture were dissolved (crosslinked polymers swollen) in methylene chloride and excess D2O. The diketene acetal/polyol(s) reaction mixture was hydrolyzed under mildly acidic conditions to yield pentaerythritol dipropionate (PDP; hydrolysis product of DETOSU). PDP was extracted into an organic phase, silylated, and analyzed by GC-MS. Fragments corresponding to the C2H5C?O+ ion (57 a.m.u.) and C2H4DC?O+ ion (58 a. m. u.) were monitored and the quantity of free ketene acetal groups were calculated from the peak areas of the chromatograms. The precision of the method was ±0.1%. The accuracy, as compared to a parallel 1H-NMR study, was within 5%. This method permits determination of the cure end-point of a poly(ortho ester) polymerization reaction to within ±0.25%. The curing kinetics agreed well with DSC branching/crosslinking measurements. © 1994 John Wiley & Sons, Inc. 相似文献
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本文以三电极体系为基础,采用脉冲伏安法测定酸性镀铜液中Cl-的含量,考察了富集电位,富集时间,电解液中CuSO4·5H2O浓度、H2SO4浓度和Cl-浓度对溶出峰电流密度的影响。实验结果表明,在酸性光亮镀铜液中,富集电位为0.30 V、富集时间为30 s时,Cl-的脉冲伏安法曲线峰形好,峰电流密度高,检测灵敏度高,Cl-检测限线性范围为0.1~20 mg/L,线性方程的方差为R2=0.9965,检测限为0.047 mg/L。本文所采用的脉冲伏安法测定酸性光亮镀铜液中Cl-含量灵敏度高、稳定性好并且抗干扰性强。利用此方法在实际生产过程中无需样品前处理即可对Cl-含量进行即时测定。 相似文献
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以羟乙基纤维素(HEC)与环氧大豆油(ESO)为原料,四氯化锡(Sn Cl4)为催化剂,二甲亚砜(DMSO)为溶剂,在室温下反应制备了羟乙基纤维素接枝环氧大豆油(ESO-HEC);ESO-HEC经碱性水解后,用酸处理得到羟乙基纤维素接枝环氧大豆油水解的酸性产物(H-ESO-HEC);再通过Na OH中和H-ESO-HEC结构中的羧酸基团,得到3种HESO-HEC-Na高分子表面活性剂。通过FT-IR表征了3种表面活性剂酸性产物H-ESO-HEC的结构;热重测试表明H-ESO-HEC比HEC具有更好的热稳定性;动态表面张力测试表明当H-ESO-HEC-Na的质量浓度升高,动态表面张力下降,且质量浓度达到临界胶束浓度时,最小表面张力值可达29 m N/m;泡沫性能测试表明随着ESO接枝量的增多,H-ESO-HEC-Na高分子表面活性剂的起泡和稳泡能力逐渐增强;通过对H-ESO-HEC-Na水溶液/庚烷的界面张力进行测试,发现不同条件制备得到的H-ESO-HEC-Na水溶液/庚烷的最低界面张力值接近,为9.8 m N/m左右。 相似文献