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建立了一种用2,4-二硝基苯肼衍生化法定量测定皮革制品中甲醛含量的方法.常温下于酸性条件中衍生20min,并对衍生条件进行了优化,与氢氧化钾液反应后所呈的物质在波长为430nm进行吸光度的测定.该法具有操作简单、快速、费用低廉的特点,可作为皮革制品中非法添加物甲醛的检测方法之一. 相似文献
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自三鹿奶粉事件后,三聚氰胺的检测也成为倍受关注的热点。目前国家标准GB/T22388—2008《原料乳及乳制品中三聚氰胺检测方法》中规定了几种检测方法,本实验参考GB/T22388—2008《原料乳及乳制品中三聚氰胺检测方法》,利用GC-MS3100建立了三聚氰胺含量的GC—MS检测方法。即用三氯乙酸水溶液超声提取乳制品中的三聚氰胺,经离心、固相萃取净化,硅烷衍生,最后由气相色谱质谱联用仪检测,外标法定量。 相似文献
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柱前衍生化反相高效液相色谱法测定大鼠血浆中牛磺酸的含量及其药动学研究 总被引:1,自引:0,他引:1
建立一种测定大鼠血浆中牛磺酸含量的柱前衍生化-高效液相色谱法,并将其应用于牛磺酸在大鼠体内的药动学研究。采用柱前衍生化高效液相色谱法,以2,4-二硝基氟苯(DNFB)为衍生化试剂,以KH2PO3缓冲液(pH7.0):乙腈∶水(70∶15∶15,v/v)为流动相,经C18色谱柱(250mm×4.6mm×5μm)分离,柱温30℃,流速1.0m L/min,进样量为20μL,牛磺酸衍生物的紫外检测波长为360 nm,并以DAS2.0计算其药动学参数。大鼠血浆中牛磺酸在1.29~1 287.5μg/m L质量浓度范围内线性关系良好,r=0.999 9,最低定量限1.29μg/m L,主要药动学参数t1/2为(3.747±1.430)h,Cmax为(949.573±192.967)μg/m L,Tmax为(1.000±0.000)h,AUC0-t为(2 862.168±565.917)(mg/L)/h。该法简单、经济、灵敏,适用于牛磺酸血药浓度测定及药动学研究。 相似文献
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本文报导了苯骈三氮唑及其衍生物、苯骈噻唑鎓盐、4—甲基—1—苯基—3—吡唑烷酮、过—硫酸复盐、EDTA铁铵盐以及硫代硫酸铵等数种照相冲洗用化学品的制备方法,并对其中某些方法作了简单的比较。 相似文献
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气相色谱-质谱法测定复合包装袋中的二氨基甲苯 总被引:1,自引:0,他引:1
用二氯甲烷作为萃取溶剂,样品中加入氯化钠降低2,4-二氨基甲苯在水中的溶解度,减压蒸馏除去样品中未反应的衍生化试剂及副产物,采用气相色谱-提取离子扫描质谱检测复合食品包装袋中二氨基甲苯的含量。方法回收率(75~95)%之间,相对标准偏差小于4.6%,检出限0.0002mg/L,满足定量分析的要求。 相似文献
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In situ derivatization/solid-phase microextraction for the determination of haloacetic acids in water 总被引:1,自引:0,他引:1
An in situ derivatization solid-phase microextraction method has been developed for the determination of haloacetic acids (HAAs) in water. The analytical procedure involves derivatization of HAAs to their methyl esters with dimethyl sulfate, headspace sampling using solid-phase microextraction (SPME), and gas chromatography-ion trap mass spectrometry (GC/ITMS) determination. Parameters affecting both derivatization efficiency and head-space SPME procedure, such as the selection of the SPME coating, derivatization-extraction time and temperature, and ionic strength, were optimized. The commercially available Carboxen-poly(dimethylsiloxane) (CAR-PDMS) fiber appears to be the most suitable for the determination of HAAs. Moreover, the formation of HAA methyl esters was dramatically improved (up to 90-fold) by the addition of tetrabutylammonium hydrogen sulfate (4.7 micromol) to the sample as ion-pairing agent in the derivatization step. The precision of the in situ derivatization/HS-SPME/GC/ITMS method evaluated using an internal standard gave relative standard deviations (RSDs) between 6.3 and 11.4%. The method was linear over 2 orders of magnitude, and detection limits were compound-dependent, but ranged from 10 to 450 ng/L. The method was compared with the EPA method 552.2 for the analysis of HAAs in various water samples, and good agreement was obtained. Consequently, in situ derivatization/HS-SPME/GC/ITMS is proposed for the analysis of HAAs in water. 相似文献
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Analysis of polar acidic herbicides has traditionally presented a challenge because of their strong adsorption to and ionic interactions with soil. One approach which has been successful for extraction of these polar compounds from soil is supercritical fluid extraction (SFE) coupled with in situ derivatization. This technique involves the addition of common derivatization reagents directly into the extraction chamber, where the acid herbicides are derivitized to extractable esters or ethers. This study describes the application of an in situ derivatization technique to pressurized fluid extraction (PFE) for the herbicides 2,4-D, 2,4,5-T, dicamba, silvex, trichlopyr, and bentazone. The efficiency of in situ derivatization PFE for these analytes is compared with a conventional basic extraction method followed by ex situ derivatization. The variables of temperature, pressure, static extraction time, and derivatization-reagent amount were optimized for recovery of these analytes from soil. Average recovery for these six analytes was 107% for in situ derivatization PFE from spiked sand, 93% for the same method from a high-concentration spiked soil (50 mg/kg), and 68% for the optimized in situ derivatization PFE method from low-concentration soil (0.5 mg/kg). The in situ derivatization PFE method has substantial advantages of simplicity of methodology and reduction in extraction time compared with the conventional technique. A second in situ derivatization PFE strategy was investigated using sodium EDTA in the extraction chamber for the extraction of 2,4-D from soil. Preliminary results demonstrate improved recovery with the use of Na4EDTA. Extraction efficiency of PFE for nonpolar organochlorine insecticides and slightly polar triazine herbicides from soil is also presented and compared with that of Soxhlet extraction. 相似文献
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A novel method for highly sensitive detection of primary and secondary amino acids with selective derivatization using acetaldehyde as a new derivatization reagent was proposed by capillary electrophoresis (CE) coupled with electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II). The precolumn derivatization of these amino acids with acetaldehyde was performed in aqueous solution at room temperature for 1 h. Upon optimized derivatization, the ECL intensities and detection sensitivities of the amino acids were significantly enhanced by 20-70 times. Using four amino acids, arginine, proline, valine, and leucine, as model compounds, their derivatives could be completely separated by CE and sensitively detected by ECL within 22 min. The linear ranges were 0.5-100 microM for arginine and proline and 5-1000 microM for valine and leucine with the detection limits of 1 x 10(-7) (0.5 fmol, arginine), 8 x 10(-8) (0.4 fmol, proline), 1 x 10(-6) (5 fmol, valine), and 1.6 x 10(-6) M (8 fmol, leucine) at a signal-to-noise ratio of 3. The derivatization reactions and ECL process of amino acids were also proposed based on in situ Fourier transform infrared and ultraviolet spectrometric analyses. 相似文献
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An in-sample derivatization headspace solid-phase microextraction method has been developed for the simultaneous determination of nonylphenol, nonylphenol mono- and diethoxylates (NP, NP1EO, NP2EO), and their acidic metabolites (NPlEC, NP2EC) in water. The analytical procedure involves derivatization of NPEOs and NPECs to their methyl ethers--esters with dimethyl sulfate/NaOH and further headspace (HS) solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) determination. Parameters affecting both derivatization efficiency and headspace SPME procedure, such as the selection of the SPME coating, derivatizationextraction time, temperature and ionic strength were optimized. The commercially available Carbowax-divinylbenzene (CW-DVB) fiber appears to be the most suitable for the simultaneous determination of both NPEOs-NPECs. Run-to-run precision of the in-sample derivatization/HS-SPME-GC/MS method gave relative standard deviations between 8 and 18%. The method was linear for NP over 2 orders of magnitude, and detection limits were compound dependent but ranged from 20 to 1500 ng/L. The SPME procedure was compared with a solid-phase extraction SPE-GC/MS method for the analysis of NPEOs-NPECs in water samples and good agreement was obtained. Therefore, in-sample derivatization HS-SPME-GC/MS can be used as a method for the simultaneous determination of short ethoxy chain nonylphenols and their acidic metabolites in water. 相似文献
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M. Claeys-Bruno O. Vandenabeele-Trambouze M. Sergent M. Geffard D. Bodet M. Dobrijevic A. Commeyras R. Phan Tan Luu 《Chemometrics and Intelligent Laboratory Systems》2006,80(2):186-197
In a previous paper (part I), new strategy was used for raising antibodies against hapten (< 300 Da) and the quantification of these hapten by ELISA using derivatization by chloroethyl nitrosourea (CENU). After raising antibodies against histamine, they were characterized and used for ELISA measurements. Optimal detection conditions were determined for the histamine quantification by ELISA method. The present study investigates the derivatization step of the histamine by chloroethylnitrosourea (CENU). Five factors (2 qualitative: nature of the solvent and nature of the antibodies and 3 quantitative: pH, % of solvent and time of derivatization) have been considered. Optimal reaction conditions were established by calculation of a validated model. 相似文献
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Detection of methamphetamine in the presence of nicotine using in situ chemical derivatization and ion mobility spectrometry 总被引:1,自引:0,他引:1
The detection of methamphetamine in the presence of nicotine has been successfully accomplished using in situ chemical derivatization with propyl chloroformate as the derivatization reagent and ion mobility spectrometry (IMS). The rapid detection of methamphetamine is important for forensic scientists in order to establish a chain of evidence and link criminals to the crime scene. Nicotine is pervasive in clandestine drug laboratories from cigarette smoke residue. It has been demonstrated that nicotine obscures the methamphetamine peaks in ion mobility spectrometers due to their similar charge affinities and ion mobilities, which makes their detection a challenging task. As a consequence, false positive or negative responses may arise. In situ chemical derivatization poses as a sensitive, accurate, and reproducible alternative to remove the nicotine background when detecting nanogram amounts of methamphetamine. The derivatization agent was coated onto the sample disk, and the derivatization product corresponding to propyl methamphetamine carbamate was detected. In the present study, in situ chemical derivatization was demonstrated to be a feasible method to detect methamphetamine hydrochloride as the carbamate derivative, which was baseline-resolved from the nicotine peak. Alternating least squares (ALS) was used to model the datasets. A mixture containing both compounds revealed reduced mobilities of 1.61 cm(2)/V.s and 1.54 cm(2)/V.s for methamphetamine and nicotine, respectively. The reduced mobility of propyl methamphetamine carbamate was found at 1.35 cm(2)/V.s. 相似文献
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Salgado-Petinal C Alzaga R García-Jares C Llompart M Bayona JM 《Analytical chemistry》2005,77(18):6012-6018
A solid-phase microextraction (SPME) procedure for the simultaneous determination of volatile alkanethiols (i.e., methane-, ethane-, propanethiol) and dihydrogen sulfide in aqueous samples as stable thioethers followed by GC/MS determination was developed. Accordingly, N-ethylmaleimide as derivatization reagent in the aqueous phase was used for the first time, improving the analyte stability and method sensitivity in comparison to the determination of free forms. Thus, pH of the aqueous medium, reaction time, and derivatization reagent concentration have been evaluated, and the main parameters affecting the SPME process (i.e., coating selection, extraction mode and time profile, extraction and desorption temperatures) optimized. At the selected derivatization and extraction conditions, the proposed method provided no matrix effect either in the derivatization reaction or in the microextraction steps. RSD values were lower than 11% and LODs from 0.74 to 5.2 ng L(-1). The developed procedure was successfully applied to different water and wastewater samples, where dihydrogen sulfide and some of the target alkanethiols were identified at low-microgram per liter concentrations. 相似文献
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A mass spectrometric method is described for the identification and counting of hydroxyl groups in an analyte. Analytes introduced into a FT-ICR mass spectrometer and ionized by positive mode ESI were allowed to react with the neutral reagent diethylmethoxyborane. This results in derivatization of the hydroxyl groups of the analytes by replacement of a proton with a diethylborenium ion. Protonated polyols react by consecutive derivatization reactions, wherein all, or nearly all, of the hydroxyls are derivatized. The polyol derivatization products are separated by 68 mass units in the mass spectrum. This 68 Da mass shift, along with 30 Da mass shifts arising from intramolecular derivatization of the primary derivatization products, makes it easy to count the number of functional groups present in the analyte. The utility of this method for the analysis of polyols as single-component solutions, as mixtures, or in HPLC effluent (LC-MS analysis) is demonstrated. 相似文献
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本文利用新型荧光试剂1,2-苯并-3,4-二氢咔唑-9-乙酸(BCAA)作为柱前衍生试剂建立了测定游离脂肪醇的方法,实验以1-乙基-3-(3-二甲氨基丙基)环己碳二亚胺(EDAC)作为缩合剂,4-二甲氨基吡啶(DMAP)为催化剂,55℃下衍生反应25min后获得稳定的荧光产物。在Eclipse XDB-C8色谱柱上,通过梯度洗脱对12种游离脂肪醇进行了分离和在线质谱定性。采用大气压化学电离源(APCI)正离子模式,对抗静电剂(十二烷基磷酸酯钾盐)中游离脂肪醇进行定性及相应含量测定。脂肪醇的线性回归系数大于0.9997,检测限在9.40-25.32fmol。 相似文献
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M. Claeys-Bruno O. Vandenabeele-Trambouze M. Sergent M. Geffard D. Bodet M. Dobrijevic A. Commeyras R. Phan Tan Luu 《Chemometrics and Intelligent Laboratory Systems》2006,80(2):176-185
Using derivatization by chloroethylnitrosourea (CENU) a new strategy was used for raising antibodies directed against hapten (< 300 Da) and the quantification of these haptens by ELISA. After raising antibodies directed against histamine, they were characterized and used for ELISA measurements. The development of a quantitative method needs an optimization of both detection and derivatization step. Experimental design methodology has been applied to optimize the conditions of the detection of the derivatized histamine. Methods and results were closely related. 相似文献