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高效液相色谱法测定烟草料液中的糖 总被引:6,自引:0,他引:6
研究了用蒸发光散射检测器检测,高效液相色谱法测定烟草料液中糖的方法。料液中的糖用固相萃取预分离,然后以Waters carbohydrate高效糖柱为固定相,V(乙腈):V(水)=70:30作为流动相分离,蒸发光散射检测器检测;样品中鼠李糖、木糖、阿拉伯糖、果糖、甘露糖、葡萄糖、蔗糖、麦芽糖8种糖的加标回收率分别为:97.0%、95.6%、102%、102.1%、95.0%、101.8%、102.6%、97.8%;线性范围分别为:鼠李糖、果糖、葡萄糖、蔗糖0.1~20pg,木糖、阿拉伯糖、甘露糖、麦芽糖0.2~25μg。相对标准偏差均小于3.2%。方法的检出限达:鼠李糖20ng、木糖26ng、阿拉伯糖28ng、果糖14ng、甘露糖20ng、葡萄糖10ng、蔗糖12ng、麦芽糖15ng,用该方法测定了烟草料液中的糖。 相似文献
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高效液相色谱法测定饮料中糖、甘油和乙醇 总被引:1,自引:0,他引:1
研究了高效液相色谱法测定饮料中糖、甘油和乙醇的方法。饮料样品用WatersSep Pak C18固相萃取小柱预分离 ,以WatersSugar Pak 1钙型阳离子交换柱为固定相 ,0 .0 5 g·L- 1ED TA钙钠水溶液为流动相 ,示差折光仪为检测器 ,一次进样测定饮料样品中的糖、甘油和乙醇。检出限在微克级 ,RSD在 0 .6 8%~ 2 .1%之间 ,标准回收率在 96 %~ 10 7%之间。方法用于几种饮料样品的测定 ,结果满意 相似文献
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高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇和醇类化合物 总被引:6,自引:0,他引:6
建立了高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇以及醇类化合物的方法。以NaOH为淋洗液,在CarboPac MA1阴离子交换柱上等度分离了肌醇、甘油、丙二醇、半乳糖醇、木糖醇、山梨醇、甘露醇、葡萄糖、果糖、蔗糖、甘露糖和半乳糖等12种化合物。对影响分离和检测的条件进行了优化,并在此优化条件下分析了烟草料液中的糖、糖醇以及醇类化合物。12种化合物的检出限为2.0~216μg/L(25.0μL进样,以3倍信噪比计算检出限)。12种化合物浓度为1~5mg/L的标准溶液连续7次进样的RSD为0.7%~4.3%。方法对烟草料液中12种化合物的加标回收率为80%~108%。方法灵敏、高效、简便、快捷。 相似文献
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蜜炼川贝枇杷膏中橙皮甙含量的固相萃取-高效液相色谱法测定 总被引:2,自引:0,他引:2
建立了蜜炼川贝枇杷膏中橙皮甙含量测定方法,样品用流动相溶解定溶后,注入Sep-Pak C18固相萃取微柱,取其达到吸附平衡后的流出液作为反相高效液相色谱法测定用的供试液,克服了高糖含量基质条件下液-液萃取法存在的提取不完全的现象;在3.265-32.65mg/L范围内,橙皮甙进样量与峰面积响应值呈良好的线性关系,r=0.9999;回收率为98%-102%,RSD为1.6%(n=5);结果表明,该法简便快速,分析结果准确可靠,重复性好,可用作蜜炼川贝枇杷膏的质量控制方法。 相似文献
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高效液相色谱法测定烟草料液中几种保润成分 总被引:2,自引:0,他引:2
甘油、丙二醇和木糖醇等多元醇是烟草料液中的重要成分,它们具有保润及定香的作用,能保持烟叶水分,增加柔韧性,减少造碎,同时还有降低刺激性和改善吃味的作用。因此准确测定烟草料液中多元醇对了解烟草料液的组成和特性有一定意义。一般情况下人们采用滴定法、比重法、旋光度法或比色法测定甘油、丙二醇和木糖醇等多元醇,但是料液中这些成分共存,会因相互干扰而使测定变得非常困难。本法研究了Waters SugarPak-1钙型阳离子交换柱为固定相,高效液相色谱法内标法同时测定料液中甘油、丙二醇和木糖醇的方法,获得了满意结果。 相似文献
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以气体扩散膜为分离装置,流动注射进样冷蒸气发生法测定了土壤中的汞。试验了载流种类,流速,浓度,还原剂的浓度,流速,载气及春流速等分析参数对测定的影响。实验中观察到Cr(Ⅵ)对汞的响应信号有负干扰。方法的线范围为0-20μg/L,检出限为0.01μg/L,在2μg/L、5μg/L含量水平测定,方法的相对标准偏差(RSD)分别为1.5%和0.54%,回收率在91%-110%之间。 相似文献
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建立了动物组织中沙丁胺醇残留量固相萃取-气相色谱-质谱分析方法。动物组织样品经过葡萄糖醛甙酶酶解后调节pH至9.5,然后用异丙醇/乙酸乙酯混合溶剂液液分配去除杂质,旋转浓缩后用乙酸铵缓冲溶液溶解经SCX固相萃取(SPE)柱净化,洗脱液经氮气吹干后用双三甲基硅基三氟乙酰氨(BSTFA)衍生,采用选择离子模式(86、350、369、440)进行测定,外标法定量。检出限为0.10μg/kg。在添加浓度0.5~5.0μg/kg范围内,平均添加回收率在66.4%~82.4%,相对标准偏差(批内)(CV)在3.5%~5.9%之间;批间(CV)在2.2%~4.8%之间。衍生物的峰面积与样品浓度在0.002~0.50mg/L范围内呈良好的线性关系,线性回归系数大于0.999。 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
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An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction. 相似文献
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The Diels-Alder reactivity of 1,2-heteroborines (H4C4B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed. 相似文献
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Xi-Liu YunWen-Ying Bi Jian-Hui HuangYu Liu Daisy Zhang-NegrerieYun-Fei Du Kang Zhao 《Tetrahedron letters》2012,53(38):5076-5080
A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd2(dba)3-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring. 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
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In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
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Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles. 相似文献