离子色谱法测定土壤中氯离子、硫酸根离子、硝酸根离子

建立离子色谱法测定土壤中Cl~–,SO_4~(2–),NO_3~–3种阴离子的含量。淋洗液为30 mmol/L KOH溶液,等浓度淋洗,流速为1.0 mL/min。Cl~–,SO_4~(2–),NO_3~–的线性范围均为0~20 mg/L,线性相关系数均大于0.999 9,检出限为0.051~0.082 mg/L,混合标准溶液测定结果的相对标准偏差为0.31~0.38%(n=10)。对土壤样品进行重复测定,3种离子测定结果的相对标准偏差均小于3%(n=7),加标回收率在95.0%~104.5%之间。该方法测定结果准确,操作简单、快速,适用于土遗址中Cl~–,SO_4~(2–),NO_3~–的测定。     

离子色谱法测定饮用水中6种阴离子

建立生活饮用水中F~–,Cl~–,PO_3^(3–),PO_4^(3–),SO_3^(2–),SO_4^(2–)6种阴离子的离子色谱检测法。采用戴安DX–120型离子色谱仪及Ion Pac AS9–HC(250 mm×4.0 mm)阴离子交换柱,以5.0 mmo L/L Na_2CO_3–0.6 mmo L/L NaHCO_3溶液为淋洗液,流量为1.2 mL/min。6种阴离子的质量浓度与其色谱峰面积呈良好的线性关系,相关系数为0.999 3~0.999 8,检出限为0.026 4~0.741 4μg/mL(S/N=3)。水样的加标回收率为91.3%~110.0%,测定结果的相对标准偏差为1.65%~3.07%(n=6)。该方法具有操作简单,选择性、准确性好等优点,能够满足饮用水中F~–,Cl~–,PO_3^(3–),PO_4^(3–),SO_3^(2–),SO_4^(2–)6种阴离子的测定要求。     

淋洗液在线发生离子色谱法测定血液透析水中的F~–,NO_3~–,SO_4~(2–)

建立血液透析水中F~–,NO_3~–,SO_4~(2–)的淋洗液在线发生–离子色谱检测法。采用ICS–1100型离子色谱仪,Ion Pac AS19型(250 mm×4 mm)色谱柱,淋洗液自动发生装置在线产生高纯度的KOH溶液作为淋洗液,流量为1m L/min,以电导检测器检测,色谱峰面积外标法定量。3种阴离子的质量浓度与色谱峰面积在测定范围内呈良好的线性关系(r≥0.999 8),检出限为0.002~0.01 mg/L,测定结果的相对标准偏差为0.26%~0.88%(n=6),加标回收率为98.0%~101.1%。该法操作简单,分析快速,灵敏度高,重现性好,能够准确检测血液透析水中的F–,NO3–,SO42–,可用于血液透析水的质量控制。     

离子色谱法快速测定牛奶中SCN~–

建立了离子色谱快速测定牛奶中SCN–的方法。采用东曹IC–2010型号离子色谱仪及TSKgel Super IC–Anion HS型阴离子快速分离柱;淋洗液为5.0 mmol/L Na2CO3溶液,流量为1.5 m L/min,柱温为40℃,进样体积为20μL,样品经乙腈去蛋白,经TOYOPAK ODS小柱除掉脂肪后,经IC–2010自动进样器自动稀释2倍后进样分析。硫氰酸根测定结果的相对标准偏差为0.94%(n=5),加标回收率为97.0%~102.8%。该方法可用于鲜奶中硫氰酸根的检测。     

电热原子吸收光谱法测定水中总钼

建立电热原子吸收法测定水中总钼的含量。样品采用硝酸–过氧化氢消解,热解涂层石墨管减小记忆效应,塞曼背景校正消除背景噪声。检测了27种共存离子的干扰影响。经6家实验室对标准物质和实际样品检测验证,方法检出限为0.6μg/L,能够满足微量检测要求。钼测定结果相对误差最大值为–6.2%,实验室内相对标准偏差为4.5%~7.6%(n=6),实验室间相对标准偏差为4.3%~5.7%(n=6),加标回收率为91.8%~104.0%。该方法精密度和准确度满足我国地下水和废水监测技术规范的质控要求。     

离子色谱法同时测定饮用水中11种无机阴离子

建立了饮用水中11种无机阴离子的离子色谱测定法。采用ISC–2100型离子色谱仪测定饮用水中的F–,S2–,Br O3–,Cl–,NO2–,NO3–,Cl O2–,Cl O3–,I–,SO42–,PO43–11种无机阴离子。水样过0.22μm滤膜后,经Ion Pac AS19离子色谱柱分离,用KOH溶液梯度洗脱,流量为1.0 m L/min,电导检测器检测,外标法定量。11种阴离子的质量浓度与色谱峰面积在测定范围内呈良好的线性关系(r≥0.999 2),检出限为0.000 7~0.005 mg/L,相对标准偏差为0.2%~4.9%(n=6),加标回收率为87.0%~104.8%。方法简便、快速,精密度和准确度高,适合于饮用水中11种无机阴离子的同时测定。     

离子色谱法检测牙膏中的亚硫酸盐

建立测定牙膏中亚硫酸盐的离子色谱法。采用Thermo Fisher Ion Pac AS11–HC和AG11–HC色谱柱,在11 mmol/L KOH溶液中分离测定牙膏中的亚硫酸根离子,亚硫酸根离子的质量浓度与色谱峰面积线性关系良好,线性方程为y=0.114 7x–0.012 3,相关系数r2=0.999 7,检测限为0.025 mg/L,测定结果的相对标准偏差为为2.2%(n=7),回收率在81.8%~90.3%之间。     

MPT–AES法测定合金钢中的硅

建立了微波等离子体炬原子发射光谱(MPT–AES)测定合金钢中的硅含量的分析方法。考察了仪器最佳实验条件、溶液酸度和钢中共存离子对测定的干扰,采用相似基体的标准钢样绘制工作曲线。硅的线性范围在0.3~7.0μg/m L之间,检出限为0.05μg/m L。测定结果的相对标准偏差为1.2%~3.1%(n=9),样品加标回收率在97.0%~103.0%之间,该法测定结果与国家标准方法测定结果相符合。MPT–AES法良好的精密度和准确度,可用于测定合金钢中硅的含量。     

ICP–OES法测定钢渣中的全铁

建立了电感耦合等离子体发射光谱(ICP–OES)测定钢渣中全铁的方法。试样用硝酸–氢氟酸消化后,经碳酸钠–硼酸混合熔剂熔解,采用ICP–OES法测定其中的全铁含量。以钢渣标准样品绘制标准曲线,Fe2O3的质量分数在0~34.33%范围内与发射强度呈良好的线性,线性相关系数r=0.999 8。标准样品测定结果的相对标准偏差为0.004 4%~0.036%(n=5),相对误差为0.80%~2.5%。用ICP–OES法与EDTA滴定法对钢渣样品进行测定,两种方法测定结果相一致。该方法简便、快速,可用于钢渣中全铁的定量分析。     

微波消解–ICP–AES法测定装甲材料中的铌含量

建立ICP–AES法测定装甲材料中铌含量的的方法。采用盐酸–硝酸–氢氟酸微波消解样品,检测器为CID固态检测器,检测波长为309.417 nm。在选定的测定条件下,标准工作曲线线性范围为0.005%~1.0%,线性相关系数为0.999 7,检出限为0.000 68%,测定结果的相对标准偏差不大于3%(n=10),加标回收率为96.0%~98.7%。该方法操作简单,测定结果准确可靠,可用于装甲材料中铌含量的测定。     

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.