铕(Ⅲ)、铽(Ⅲ) β-二酮配合物的制备及表征

醋酸铕、醋酸铽分别与乙酰丙酮在60°C水浴下加热回流,生成两种稀土β-二酮配合物,即乙酰丙酮铕(Eu(acac)3?3H2O)和乙酰丙酮铽(Tb(acac)3?3H2O),在紫外灯下观察配合物发光现象,乙酰丙酮铕在紫外灯下显暗红色,乙酰丙酮铽在紫外灯下显亮绿色。红外分析结果与理论相吻合,荧光分析表明它们是较好的荧光材料,热分析结果说明它们的热稳定性相对较高。     

室内用水性涂料及水性胶粘剂中甲醛含量测定的研究

阐述了GB18582和GB18583中对于应用乙酰丙酮分光光度法测定游离甲醛的分析方法之间的差异,主要包括乙酰丙酮试剂要求、标准曲线绘制、测定波长和样品前处理等.在详细分析区别的基础上,对标准方法进行改进,提出适合水性涂料和水性胶粘剂中游离甲醛的测定方法,该方法操作简单,具有较高的精密度和准确度.     

固相微萃取-气相色谱-质谱法测定火场残留物中白酒类助燃剂北大核心CSCD

白酒主要指中国白酒。白酒是含乙醇较高的一种水溶性液体饮料,其主要成分是乙醇、水,极少的成分是酸、酯、醇、醛等有机化合物。白酒的种类繁多,乙醇含量较高的白酒有良好的燃烧性能,可被犯罪分子用来作为放火的助燃剂,因此目前对白酒类助燃剂的正确分析鉴定对于放火案件的侦破具有非常重要的意义。火场残留物中白酒类物质的提取和鉴定向来是火场助燃剂提取鉴定技术的难题。     

固相微萃取-气相色谱-质谱法测定火场残留物中白酒类助燃剂

正白酒主要指中国白酒。白酒是含乙醇较高的一种水溶性液体饮料,其主要成分是乙醇、水,极少的成分是酸、酯、醇、醛等有机化合物。白酒的种类繁多,乙醇含量较高的白酒有良好的燃烧性能,可被犯罪分子用来作为放火的助燃剂,因此目前对白酒类助燃剂的正确分析鉴定对于放火案件的侦破具有非常重要的意义。火场残留物中白酒类物质的提取和鉴定向来是火场助燃剂提取鉴定技术的难题。由于火灾现场通     

过渡金属乙酰丙酮螯合物的体积排除色谱研究

用定量体积排除色谱方法研究了过渡金属Fe(Ⅲ)、Co(Ⅲ)、Cu(Ⅱ)、Ni(Ⅱ)的乙酰丙酮螯合物在四氢呋喃溶液中的加合和缔合行为。在溶液中乙酰丙酮钴(Ⅲ)以单个螯合物分子的形式存在,乙酰丙酮铜(Ⅱ)和乙酰丙酮铁(Ⅲ)与溶剂加合生成加合物,乙酰丙酮铁(Ⅲ)除加合物外还存在缔合度为2-10的多分散缔合物,乙酰丙酮镍(Ⅱ)水合物在四氢呋喃中产生了加合交换作用,同时存在缔合度为6左右的缔合物。色谱数据给出了螯合物、加合物及缔合物     

聚乙二醇基质中纳米乙酰丙酮铽的荧光特性研究

在高分子聚乙二醇基质中制得了纳米乙酰丙酮铽的络合物并对其荧光特性进行了研究。结果表明,纳米乙酰丙酮铽的荧光光谱在峰位、峰形、峰强和主峰的半高宽等方面都与普通乙酰丙酮铽有明显差别。     

高效液相色谱法同时测定乙酰丙酮反应液中的乙酰丙酮和丙酮

建立了一种同时检测乙烯酮-丙酮法制乙酰丙酮反应液中乙酰丙酮和丙酮的高效液相色谱法(HPLC)。采用Agilent Eclipse XDB-C18色谱柱,以四氢呋喃-水(15:85, v/v)溶液为流动相(用0.1 mol/L磷酸二氢钠缓冲盐调节pH为4.0～5.0),流速0.6 mL/min,紫外检测波长270 nm,采用外标法定量。在优化的条件下,乙酰丙酮和丙酮的线性范围分别为0.01～50.00 mg/L和0.01～30.00 mg/L,相关系数均为0.9999以上。使用HPLC测定乙酰丙酮和丙酮的含量,其相对标准偏差均小于1.0%,结果表明方法的重复性好;反应液中添加乙酰丙酮和丙酮的加标回收率均为99.00%～101.50%。与应用紫外分光光度法测定乙酰丙酮的结果相比,平均相对误差为1.48%。所建立的方法为用丙酮生产乙酰丙酮等类似混合体系中乙酰丙酮的定量分析提供了依据,同时为酮类化合物的测定提供了准确、便捷的方法。     

过渡金属乙酰丙酮螯合物的体积排除色谱研究

用体积排除色谱方法研究了过渡金属Fe(Ⅲ)、Co(Ⅲ)、Cu(Ⅱ)、Ni(Ⅱ)的乙酰丙酮螯合物在四氢呋喃溶液中的加合和缔合行为。在溶液中乙酰丙酮钴(Ⅲ)以单个螯合物分子的形式存在,乙酰丙酮铜(Ⅱ)和乙酰丙酮铁(Ⅲ)与溶剂加合生成加合物,乙酰丙酮铁(Ⅲ)除加合物外还存在缔合度为2-10的多分散缔合物,乙酰丙酮镍(Ⅱ)水合物在四氢呋喃中产生了加合交换作用,同时存在缔合度为6左右的缔合物。色谱数据给出了螯合物、加合物及缔合物的相对含量。螯合物与相同分子量的聚苯乙烯相比,其保留体积的滞后以Ni相似文献   

盐化-减压浓缩-高效液相色谱法测定酱香白酒中乳酸和乙酸的含量北大核心CSCD

酱香白酒是中国最受欢迎的白酒之一,其中的两种有机酸乳酸与乙酸对白酒口 感的 影响较为强烈,一直是行业研究的热点。目前,白酒中有机酸的分析方法主要有高效液相色谱法[1-2]、气相色谱-质谱法[3-4]和离子色谱法[5]等。相较于其他香型白酒,酱香白酒的酒精度数大多在53°左右,含有更多种类的风味物质[6-7],这些复杂的物质与较高的酒精度数会给乳酸和乙酸的定量分析产生干扰。因此,在定量分析时往往需要对酒样进行适当的前处理。     

白酒中C_9－C_（18）脂肪酸的气相色谱分析

白酒中Ｃ＿９－Ｃ＿（１８）脂肪酸的气相色谱分析周在德，曾永昌（四川大学化学系成都６１００６４）关键词气相色谱法，白酒，Ｃ＿９－Ｃ＿（１８）脂肪酸。白酒中脂肪酸的含量及相互比例关系，极大地影响着白酒的色，香，味，风格￣（［１］［２］）。一般采用的化学分...     

The fluorimetric determination of formaldehyde

A sensitive fluorimetric procedure for formaldehyde has been developed. The method, which can measure 0.01 μg formaldehyde, is based on the Hantzsch reaction between acetylacetone, ammonia, and formaldehyde. The product, 3,5-diacetyl-I,4-dihydrolutidine, is colored yellow and fluoresces yellow green. Infra-red spectra indicate that this compound is ionic in dilute solution and aggregated in concentrated solution. The Hantzsch reaction may be extended for the assay of other aldehydes, amines, and β-diketones.     

非水体系中电解镍中间产物制备纳米NiO

采用纯镍为阳极，乙酰丙酮和乙醇的混合溶液中加入少量有机胺导电盐为电解液，施加一定电流使镍溶解，然后将电解液直接水解，控制一定的水解条件，制备得到纳米NiO粉体. 采用拉曼光谱、红外光谱、元素分析、XRD 和TEM 分别对电解得到的纳米NiO前驱体和纳米NiO进行了分析与表征, 并探讨了电化学溶解镍金属法制备纳米NiO反应的影响因素.电化学溶解镍金属得到的前驱体为Ni(OEt)2(acac)2,这种不溶性镍醇盐配合物升温至40～50℃即可溶解于乙醇溶液中,可直接应用于溶胶 凝胶(Sol gel)过程.水解后的纳米NiO呈无定形结构, 350 ℃煅烧后形成立方晶型NaCl结构, 纳米NiO经600 ℃煅烧后粒径分布在5～10 nm. 该方法理论上为二价不溶性金属醇盐经溶胶 凝胶工艺制备纳米氧化物材料提供了一条新的途径.     

Combined use of supported liquid membrane and solid-phase extraction to enhance selectivity and sensitivity in capillary electrophoresis for the determination of ochratoxin A in wine

This paper proposes a novel strategy to enhance selectivity and sensitivity in CE, using supported liquid membrane (SLM) and off-line SPE simultaneously. The determination of ochratoxin A (OA) in wine has been used to demonstrate the potential of this methodology. In the SLM step, the donor phase (either a 20 mL volume of a standard solution at pH 1 or a wine sample at pH 8) was placed in a vial, where a micromembrane extraction unit accommodating the acceptor phase (1 mL water, pH 11) in its lumen was immersed. The SLM was constructed by impregnating a porous Fluoropore Teflon (PTFE) membrane with a water-immiscible organic solvent (octanol). In the off-line SPE step, the nonpolar sorbent (C-18, 4 mg) selectively retained the target ochratoxin, enabling small volumes of acceptor phase (1 mL) to be introduced. The captured analytes were eluted in a small volume of methanol (0.1 mL). This procedure resulted in sample cleanup and concentration enhancement. The method was evaluated for accuracy and precision, and its RSD found to be 5%. The LODs for OA in the standard solutions and wine samples were 0.5 and 30 microg/L, respectively. The results obtained demonstrate that SLM combined with off-line is a good alternative to the use of immunoaffinity columns prior to CE analysis.     

超快速液相色谱-串联质谱法测定黄酒和葡萄酒中山梨酸等9种防腐剂和甜味剂

建立了一种专属、灵敏的同时测定黄酒和葡萄酒中安赛蜜、糖精、甜蜜素、阿斯巴甜、苯甲酸、山梨酸、甜菊糖苷、纽甜和脱氢乙酸等9种防腐剂和甜味剂的超快速液相色谱-串联质谱(UFLC-MS/MS)分析方法。不同类型的黄酒和葡萄酒经纯水稀释后,以乙腈和0.01%三氟乙酸-2.5 mmol/L乙酸铵水溶液为流动相,采用梯度洗脱方式在Shim-pack XR-ODSII色谱柱(100 mm×2.0 mm, 2.2 μm)上进行分离,以电喷雾负离子多反应监测(MRM)模式进行质谱分析。实验表明,9种防腐剂和甜味剂在检测范围内均具有良好的线性关系(r2＞0.998);方法的检出限(以信噪比大于3计)为0.03～15.0 μg/L,定量限(以信噪比大于10计)为0.1～50.0 μg/L;在黄酒中的回收率为96.2%～100.5%,相对标准偏差(RSDs)为0.6%～5.4%;在葡萄酒中的回收率为96.0%～104.0%, RSDs为0.7%～4.8%。同时研究了这9种防腐剂和甜味剂的二级质谱特征,阐释了其二级质谱裂解途径。本方法灵敏度高、重现性好、分析速度快,可用于黄酒和葡萄酒中防腐剂和甜味剂的快速确证检测。     

Bilirubin and hemoglobin interferences in direct colorimetric cholesterol reactions using enzyme reagents

The interferences of bilirubin and hemoglobin were tested in two cholesterol procedures in which enzymes were used as chemical reagents. Both procedures used similar approaches with cholesterol esterase to free cholesterol from its esters and cholesterol oxidase to generate hydrogen peroxide from the total free cholesterol resulting. From that common start, one procedure then used catalase to generate formaldehyde from methanol and the peroxide produced from cholesterol, and the formaldehyde was then reacted with acetylacetone to produce a yellow chromogen, while the other procedure used peroxidase to catalyze a reaction directly between peroxide and 4-aminoantipyrine plus phenol to generate a pink chromogen. Bilirubin and hemoglobin were shown to produce some interference by reacting competitively with peroxide in both systems and by contributing residual absorbance at the wavelengths of measurement of each of the chromogens. Since bilirubin showed a spectral change, static blanking with sample blanks caused overcorrections. However, the elimination of a sample blank for either procedure could result in a favorable compensating error because the residual color of bilirubin could substitute in part at least for the lost reactivity of the peroxide used up in reaction with the bilirubin of the sample.     

Optimization of a procedure for the selective isolation of some powerful aroma thiols. Development and validation of a quantitative method for their determination in wine

This paper deals with the isolation properties of four relevant wine mercaptans in two different separation systems and with the subsequent development, optimization and validation of an analytical procedure for their quantitative determination. 4-Methyl-4-mercaptopentanone (4M4MP), 2-furanmethanethiol (FFT), 3-mercaptohexanol (3MH) and 3-mercaptohexyl acetate (AMH) can be quantitatively extracted from 200 ml of wine in a bed packed with 1 g of LiChrolut EN resins. Fatty acids and diverse interfering compounds are removed by rinsing with an aqueous solution with a 40% of methanol and buffered at pH 7.2 with alpha,alpha,alpha-tris-(hydroxymethyl)-aminomethane (TRIS) 0.2 M. Mercaptans can be further isolated by extraction with an aqueous solution of 1 mM p-hydroxymercury benzoate. Best results were achieved with an extraction with a solution at pH 10.7 with 0.2 M 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), further acidification to pH 7.5, release of thiols by the addition of dithioerythritol and extraction with 2 x 0.75 ml dichloromethane. The extract is concentrated to 200 and 20 microl are finally injected in a gas chromatograph-ion trap mass spectrometric system. Method detection limits are 0.8, 6, 15 and 5 ng l(-1) for 4M4MP, FFT, MH and AMH, respectively. The recovery in the sample pre-treatment was 76, 45, 75 and 95%, respectively. Repeatability and linearity are also satisfactory. Different critical aspects, such as the effect of air or the evaporation of the extract were also studied.     

Determination of clozapine and its metabolites in serum and urine by reversed phase HPLC

A rapid, specific and sensitive method using reversed phase HPLC for the simultaneous determination of clozapine and its two metabolites in serum and urine has been developed. The mobile phase was a mixture of 67% (v/v) methanol in water containing 0.4% tetramethylethylenediamine and 0.32% acetic acid (pH 5.5). The influence of methanol content, the pH of the mobile phase and the effect of adding alkylammonium ions as peak tailing reducer in the mobile phase have been investigated. The solvent for extracting clozapine from serum and urine was ether. 50 microliters of 0.25 M H2SO4 solution was used to redissolve the dry residue to eliminate the endogenous compounds which could otherwise be eluted together with clozapine from the HPLC column. The analysis of a single sample was accomplished within half an hour. The identities of the chromatographic peaks of clozapine and its N-demethyl metabolite collected from the patient urine sample were confirmed by mass spectrometry. The method is sufficiently sensitive (5 ng/ml) and reproducible (CV 2.9%-6.7%) for clinical and pharmacokinetic studies, and preliminary results in these respects are presented.     

赖氨酸-甲醇-1,2-萘醌-4-磺酸钠体系褪色光度法测定甲醇

赖氨酸与1,2-萘醌-4-磺酸钠在碱性条件下发生亲核取代反应,生成红褐色的产物,在该体系中加入甲醇后发生褪色反应,褪色最大波长λmax=559 nm,甲醇质量浓度在0.050～7.61 g/L范围内与吸光度降低程度呈良好线性关系,线性回归方程为A=-0.005 17-0.086 79c(g/L),线性相关系数r=0.999 6,检测限为49.5 mg/L,平均回收率为99.1%～102.6%。 用于甲醇样品测定,结果满意。     

Gas chromatographic quantitative analysis of methanol in wine: operative conditions, optimization and calibration model choice

The influence of the wine distillation process on methanol content has been determined by quantitative analysis using gas chromatographic flame ionization (GC-FID) detection. A comparative study between direct injection of diluted wine and injection of distilled wine was performed. The distillation process does not affect methanol quantification in wines in proportions higher than 10%. While quantification performed on distilled samples gives more reliable results, a screening method for wine injection after a 1:5 water dilution could be employed. The proposed technique was found to be a compromise between the time consuming distillation process and direct wine injection. In the studied calibration range, the stability of the volatile compounds in the reference solution is concentration-dependent. The stability is higher in the less concentrated reference solution. To shorten the operation time, a stronger temperature ramp and carrier flow rate was employed. With these conditions, helium consumption and column thermal stress were increased. However, detection limits, calibration limits, and analytical method performances are not affected substantially by changing from normal to forced GC conditions. Statistical data evaluation were made using both ordinary (OLS) and bivariate least squares (BLS) calibration models. Further confirmation was obtained that limit of detection (LOD) values, calculated according to the 3sigma approach, are lower than the respective Hubaux-Vos (H-V) calculation method. H-V LOD depends upon background noise, calibration parameters and the number of reference standard solutions employed in producing the calibration curve. These remarks are confirmed by both calibration models used.     

电化学方法制备纳米NiO及反应机理初探

采用电化学法一步制备了镍醇盐配合物Ni(OEt) 2 (acac) 2 (acac为乙酰丙酮基 ) ,并以其作为前驱体 ,控制一定水解条件制得胶体 ,分别在 4 5 0℃ ,60 0℃煅烧均得到具有立方晶型的纳米NiO粉体 .通过红外光谱 (FT_IR)、核磁共振 (1HNMR)、拉曼光谱 (Ramanspectrum)、X_射线粉末衍射 (XRD)、透射电子显微镜 (TEM)等手段对前驱体和NiO粉体进行了表征 .结果表明 ,电解合成的最佳温度为 30～ 4 0℃ ,不溶性镍醇盐配合物升温到 4 0～ 5 0℃即可溶解 .电解法制备得到的纳米NiO层呈球形单分散结构 ,粒径在 10～ 15nm左右 .本文同时讨论了电合成纳米NiO的反应机理