超高效液相色谱法测定卷烟烟丝中7种水溶性糖含量

以ACQUITY UPLC BEH Amide柱为分析柱,乙腈－0．2％三乙胺一水作为流动相,建立了超高效液相色谱－蒸发光散射检测器测定卷烟烟丝中鼠李糖、木糖、果糖、甘露糖、葡萄糖、蔗糖、麦芽糖7种水溶性糖的分析方法。7种水溶性糖回归方程的线性相关系数均大于0．999,检出限为0．56～1．11μg／mL。7种水溶糖的回收率在90．43％106．41％之间,相对标准偏差为1．66％－4．35％仰：6）。该方法灵敏度、准确度高,稳定性好,可用于大批量卷烟烟丝中水溶性糖含量的测定。     

高效液相色谱法测定烟草料液中的糖

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。     

高效液相色谱-蒸发光散射检测法在烟用香精料液中水溶性糖及山梨醇分析中的应用

建立了高效液相色谱-蒸发光散射(HPLC-ELSD)同时检测烟用香精料液中6种水溶性糖及山梨醇的分析方法。方法选用Isolute ENV+固相萃取(SPE)小柱净化样品提取液,以Prevail Carbohydrate ES高效糖柱(250 mm×4.6 mm, 5 μm)作为分析柱,以乙腈和水(75:25, v/v)作为流动相,在1.0 mL/min流速下实现目标物的良好分离;蒸发光散射检测器漂移管温度为79 ℃,载气流速为2.0 L/min。方法针对各目标物建立双对数工作曲线,线性范围约为0.06～1.2 g/L,检出限为12～26 mg/L,样品加标回收率为88%～109%。针对蒸发光散射检测器的双对数工作曲线,通过实验进行分析对比,并结合前人的工作,指出目标物的物理化学性质及其在色谱柱上的保留状态和流动相的洗脱能力等都是影响检测信号的因素。     

快速溶剂萃取-离子色谱法测定茶叶中的有机酸

建立了快速溶剂萃取-离子色谱法（ASE—IC）测定茶叶中的9种有机酸。优化了ASE苹取条件,以水为萃取溶剂,80℃下萃取5min,循环两次。采用Ionpac AS11HC柱分离,KOH溶液梯度洗脱,流速1,0mL／min,抑制电导检测。9种有机酸的检出限为0．009-0．160μg／mL,线性范围为0．5—10μg／mL,相关系数大于0．999,加标回收率为93．4％-99．2％,相对标准偏差为1．4％-4．1％。     

吖啶橙共振光散射法测定痕量脱氧核糖核酸

研究了三环杂芳香类染料吖啶橙(AO)与DNA作用的共振光散射光谱,在pH11．5～12．5的范围内,加入DNA导致吖啶橙共振光散射增强,在339nm处,存在一共振光散射增强峰,其强度与DNA浓度呈线性关系,据此建立了一种测定DNA的共振光散射新方法?对于ctDNA,方法的线性范围为14．3～1000μg／L,检出限为2．86μg／L,RSD为3．6％;对于fsDNA,方法的线性范围为24．0～1250μg／L,检出限为4．78μg／L,RSD为6．0％。已用于合成样品中DNA的测定。     

GPC—HPLC—RP法检测熏烧烤肉制品中的苯并（a）芘

采用MPS全自动样品净化系统中的GPC凝胶渗透色谱净化熏烧烤肉制品中的苯并（a）芘（BaP）,并用高效液相色谱荧光法（HPLC—RP）测定BaP的含量。GPC条件：GPC凝胶渗透色谱柱,以环己烷-乙酸乙酯（体积比50：50）为流动相,流速4．7mL／min,收集时间为15—21min。HPLC条件：Diamonsil C18色谱柱（250mm×4．6mm,5μm）;流动相：乙腈-水（体积比88：12）,流速为1．0mL／min;柱温：30℃;进样量：10μL;激发波长：384nm;发射波长：406nm。该方法线性关系良好,加标回收率为82．4％～91.3％,相对标准偏差小于5％,检出限为0．15μg／kg。方法简化了手工操作,有效地去除了熏烧烤肉制品中的色素及脂肪干扰,可应用于熏烧烤肉制品中BaP的测定。     

固相萃取-高效液相色谱法测定水中的多环芳烃

建立了固相萃取-一高效液相色谱法测定水中多环芳烃的方法。水样经L-18固相萃取柱吸附后用二氯甲烷洗脱,氮吹干后换甲醇溶剂。反相C18柱为色谱柱;水、甲醇为流动相进行梯度洗脱,流速为1．0mL／min;柱温为30℃;检测器为荧光检测器、紫外检测器。方法的检出限为0．00006-0.03μg／L,回收率为80％～110％,测定结果的相对标准偏差为0．1％～3．6％（n=5）。方法适合于水中16种多环芳烃的测定。     

鳗鱼、饲料中恩诺沙星残留的测定及真假阳性辨别

采用反相高效液相色谱法(RP-HPLC),测定鳗鱼、饲料中的恩诺沙星药物残留．在Waters Nova-Pak C18柱上,用荧光检测器,激发波长280nm;发射波长450nm．流动相为5mmol／L NaH2PO4溶液-乙腈溶液(体积比为70：30),磷酸调pH值为2．7,流速1．2mL／min,柱温40℃．在鳗鱼、饲料中的最低检测限分别达到1μg／kg和2μg／kg,标准曲线在30—500ng／mL线性范围内相关系数达0．9997．在3种浓度水平对鳗鱼组织和饲料中的3种浓度进行回收率测定,其回收率在76％～98％之间;变异系数RSD小于8％,符合痕量测定要求．还对如何辨别真假阳性进行特别介绍．     

高效液相色谱-蒸发光散射检测法同时测定固态食品中6种稀有糖

稀有糖在固态食品中的应用量与日俱增，引发了掺假、过量添加等食品安全问题，因此建立固态食品中稀有糖(阿洛酮糖、塔格糖、海藻糖、异麦芽酮糖、赤藓糖醇和甘露糖醇)的检测方法十分重要。本文基于高效液相色谱-蒸发光散射检测器，建立了一种同时检测固态食品中6种稀有糖的分析方法。选用Zorbax Original NH₂色谱柱(250 mm×4.6 mm, 5μm)进行分离，流动相为乙腈-水(80∶20, v/v),流速梯度洗脱。蒸发光散射检测系统的漂移管温度设置为50℃,雾化器载气为高纯氮，载气流速为1.0 mL/min,压力为275.79 kPa,增益值为3。样品经25 mL水提取，振荡涡旋10 min,分别加入200μL的乙酸锌溶液和200μL的亚铁氰化钾溶液净化，4 500 r/min离心10 min,取上清液1 mL,过0.22μm水相滤膜，待上机分析。6种稀有糖在各自范围内线性关系良好，决定系数(R²)均>0.998 5,方法的检出限为0.02～0.60 g/100 g。以空白固态食品样品为基质，在3种加标水平下，6种稀有糖的回收率为92...     

溴化十六烷基吡啶的双波长共振光散射比率法测定

应用双波长共振光散射（DW—RLS）比率法研究了溴百里酚蓝（BTB）与阳离子表面活性剂溴化十六烷基吡啶（CPB）的相互作用。在pH1．5的乙酸钠-HCl缓冲溶液中,CPB本身的共振光散射很弱,BTB有一定的共振光强度,加入CPB后BTB的共振光信号显著增强,最大散射峰位于523nm,且散射光强度与CPB的浓度呈线性关系,可以通过单波长共振光散射法检测CPB,CPB质量浓度的线性范围和检出限分别为0．05—0．60mg／L和42μg／L。使用248nm和424nm两波长处散射强度比值（I248／I424）代替单波长处的共振光散射强度测定CPB,其线性范围和检出限分别为0．03～1．0mg／L和3μg／L。与共振光散射法相比较,DW—RLS比率法受酸度、离子强度等环境条件影响较小,并且有更宽的线性范围和更低的检出限,应用于合成和实际水样中CPB的测定,获得较好的结果。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.