Solid Phase Extractive Preconcentration of Cobalt and Nickel in Hair Samples Using Ethyl Xanthate Modified Benzophenone

The ethyl xanthate complexes of cobalt and nickel are quantitatively retained on benzophenone in the pH range of 8.0–10.0. The solid mixture consisting of metal complex together with benzophenone is dissolved in 5mL of dimethyl formamide, and the cobalt and nickel contents were determined by flame atomic absorption spectrometry. The calibration graphs are rectilinear over the concentration range of 0–75 (Co) and 0–100 (Ni) µgL^–1. The detection limits of flame AAS for cobalt and nickel are lowered by a factor of 200 due to the solid phase extraction preconcentration procedure. NIES CRM Human Hair No. 5 and IAEA Reference Hair HH-1 certified reference materials were used in order to verify the accuracy of the developed preconcentration method in analysing human hair samples. The results obtained were found to be in excellent agreement with certified values. Furthermore, hair samples collected from various inhabitants of different age groups and sex living in the Indian states of Andhra Pradesh and Tamil Nadu were successfully analysed by flame AAS in conjunction with the solid phase extraction preconcentration procedure developed for cobalt and nickel.     

Leach of Cesium and Barium from Sol-Gel Derived Zincborosilicate and Borosilicate Glasses

Borosilicate and zincborosilicate glass powders containing up to 20 wt.% of cesium and barium oxide were prepared by the sol-gel method and characterized by XRD and SEM. Monolithic samples of borosilicate and zinc borosilicate glasses were prepared by pressing and annealing the above powders. Leach rates of barium and cesium from the samples in water were measured as a function of time. Leach rates of cesium and barium from zincborosilicate were significantly lower than borosilicate glass, and barium showed higher leachability than cesium in all the prepared glasses.     

羟丙哌嗪分子印迹的固相萃取

以L-羟丙哌嗪为模板分子, α-甲基丙烯酸为功能单体, 三羟甲基丙烷三甲基丙烯酸酯为交联剂, 合成了羟丙哌嗪分子印迹聚合物, 利用该聚合物进行羟丙哌嗪固相萃取应用研究. 实验证明, 所合成的分子印迹聚合物具有良好的识别萃取模板分子羟丙哌嗪的能力, 能够用于羟丙哌嗪的富集浓缩, 而空白聚合物却不具备这样的特性. 考察了模板分子与其结构类似物苄基哌嗪、N-异丙基哌嗪和乙氧基羰基哌嗪的固相萃取分离情况, 研究表明, 虽然其中的苄基哌嗪在印迹材料上具有最强的保留, 但是通过先后使用不同的洗脱溶液实现了模板分子与苄基哌嗪的选择性分离.探讨了印迹识别机理,并用PM3 半经验计算机模拟方法进行了辅助分析验证.     

Metal Sorption,Solid Phase Extraction and Preconcentration Properties of Two Silica Gel Phases Chemically Modified with 2-Hydroxy-1-Naphthaldehyde

Active silica gel phase (I) was chemically modified to the corresponding amino- (SiNH₂) and chloro- (SiCl) derivatives via silylation reactions. These were used to synthesize two newly modified silica gel phases (II, III) by direct chemical reaction with 2-hydroxynaphthaldehyde (2-HNA). The surface coverage values are 370, 432µmolg^–1 and 320, 355µmolg^–1 for (II) and (III), on the basis of thermal desorption and metal probe testing method, respectively. The metal sorption properties of silica gel phases (II, III) were studied and compared with active silica gel phase (I). The maximum determined metal capacity values were found to be 10–110, 20–290 and 20–370µmolg^–1 for phases I, II and III, respectively. The distribution coefficient values (K_d) were also determined for a series of metal ions, and the results showed that the two new chemically modified phases (II and III) were highly selective for Cu²⁺, Zn²⁺, Cd²⁺, Hg²⁺ and Pb²⁺. The potential applications of silica gel phases (II, III) as solid phase extractors for the same five metal ions spiked in drinking tap water (1.000µgmL^–1) were found to give percentage recovery values in the range of 90.2–96.3±4.1–6.3%, while pre-concentration of the same five metal ions spiked in drinking tap water (50.0ngmL^–1) was successfully accomplished with a percentage recovery range of 92.6–95.8±4.8–5.7%.Received December 16, 2002; accepted May 14, 2003 published online September 1, 2003     

Enhanced Selectivity and Sensitivity for Flow Injection Spectrophotometric Determination of Cobalt Using Solid Phase Extraction with a 2D Ion-Imprinted Adsorbent

The present work reports the effectiveness of a 2D imprinting method based on a surface imprinting technique for the development of a selective and sensitive flow sorbent preconcentration system for Co²⁺ ion determination. Cobalt ions were determined by UV-vis spectrophotometry exploiting the complexation with 1-(2-piridylazo)-2-naphtol (PAN). Based on a coefficient of relative selectivity (k'), the ion-imprinted amino-functionalized silica gel sorbent (ISG), compared with modified but non-imprinted sorbent (MSG) and silica gel (SG), showed a very high selectivity. A limit of detection of 0.51 µg L^?1 and precision (n = 10) as a relative standard deviation of 2.63 and 1.50% for Co²⁺ concentration of 10.0 and 90.0 µg L^?1, respectively, were achieved. A comparison of the proposed method with other previously published methods shows advantages in terms of sample consumption, sample throughput, and limit of detection. The application of the present method was successfully performed for the direct determination of Co²⁺ content in urine and environmental water samples without any interference and without sample preparation, with satisfactory results.     

印迹聚合物改性多壁碳纳米管固相萃取熊果酸

以聚乙二醇改性的碳纳米管为基质,熊果酸为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用沉淀聚合法成功制备碳纳米管-印迹复合材料.采用红外光谱和扫描电镜研究该复合印迹材料的结构和形貌.结果表明,在碳纳米管表面接枝一层稳定且均匀的印迹材料.采用静态吸附实验研究此印迹材料的吸附性能,...     

Solid Phase Extraction Chemiluminescence Determination of Methamidaphos on Vegetables

IntroductionDuring recent years,organophosphorus pesticides(OPPs)have been widely used in agriculture becauseof their low environmental persistence and high effec-tiveness.However,they have a high acute toxicity.Trace amounts of OPPs may remain in foodstu…     

分子印迹技术在固相萃取中的应用

对2000-2010年间国内外文献报道的有关分子印迹技术在固相萃取中的应用进行了综述。主要内容包括分子印迹技术和固相萃取技术的原理、分子印迹聚合物的制备和分子印迹-固相萃取的两种操作模式,着重介绍了分子印迹-固相萃取在环境、食品、生物医药等领域中的应用(引用文献32篇)。     

Determination of Methylamines and Methylamine-N-oxides in Particulate Matter Using Solid Phase Extraction Coupled with Ion Chromatography

Currently, the concentrations of methylamines in fine particulate matter (PM) are most often measured by aerosol time-of-flight mass spectrometry. A novel method for identification and determination of methylamines and methylamine-N-oxides in fine particles based on solid phase extraction (SPE) coupled with ion chromatography (IC) was developed. The experimental conditions including SPE conditions and chromatographic conditions were optimized. The quartz filter loaded with particulate matter (PM) samples was ultrasonically extracted with 20 mL of methanol and water (1:3, V/V) and the extraction process was repeated twice. After extraction, a total of 60 mL of extraction solvent was dropped into the extraction equipment for SPE. The Agilent AccuBond C₁₈ was chosen for enriching the methylamine, dimethylamine, trimethylamine and trimethylamine-N-oxide in fine particles. Under the optimum conditions, the target species on Agilent AccuBond C₁₈ were washed by 0.5 mL of acetonitrile solution and then concentrated (2 mL) before injecting into IC for analysis. A PRP X-200 (250 mm × 4 mm i.d.) was used for separation of analytes at 25 °C. The mobile phase was a mixture of 3% (V/V) acetonitrile solution and 5 mM nitric acid with the flow rate of 1 mL min^–1. The four aliphatic amine species were fully resolved and completely separated within 30 min. The linearity of the four compounds ranged from 0.45 μg kg^–1 to 1000 μg kg^–1 with precisions of 2%–4% and detection limits of 0.002–0.003 μg m^–3. The recoveries of the four aliphatic amine species in real PM samples were higher than 90%. This method was successfully applied in the analysis of real fine PM samples collected in Beijing. The concentrations of trimethylamine and methylamine-N-oxides were in the range of (0.01 ± 0.001) μg m^–3–(0.08 ± 0.002) μg m^–3 and (0.05 ± 0.001) μg m^–3–(0.14 ± 0.002) μg m^–3 for Beijing dust and haze PM samples, respectively.     

固相萃取-超高效液相色谱法测定水体中4种硝基呋喃类药物

采用固相萃取-超高效液相色谱法测定水体中呋喃西林、呋喃它酮、呋喃妥因、呋喃唑酮等4种硝基呋喃类药物的含量。样品经HLB固相萃取柱净化后,用氨水-甲醇(5+95)溶液洗脱。以BEH C18色谱柱为分离柱,以乙腈和含有0.1%(体积分数)甲酸的2mmol·L-1乙酸铵溶液以体积比23比77组成的混合液为流动相,在检测波长360nm处进行测定。4种硝基呋喃类药物的质量浓度均在5.0~200μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.02μg·L-1。以空白样品为基体进行加标回收试验,所得回收率在84.5%~97.2%之间,测定值的相对标准偏差(n=6)在1.5%~4.5%之间。     

Interpretation of the Role of Composition on the Inclusion Efficiency of Monovalent Cations into Cobalt Hexacyanoferrate

Cobalt hexacyanoferrate of various compositions was prepared in flow mode and the role of the vacancy on the structure, thermogravimetric (TG) properties, and the adsorption efficiency was studied. The material, Na_yCo[Fe(CN)₆]_1−x ⋅ z H₂O, with a minimum vacancy of x=0.014 to the highest x=0.47, was obtained. The TG-differential scanning calorimetry (DSC) profile showed a distinct influence of the vacancy on the water release temperature. Materials with x>0.35 showed a smooth release of water at a relatively lower temperature. However, for the materials with x<0.35, water release took place in multiple steps, suggesting the existence of various forms of water. The FTIR profiles supported the existence of free and bonded water molecules. However, the materials with multiple water peaks in the FTIR spectra showed a shift of the major XRD peaks when heated at 285 °C in N₂ atmosphere. Regarding the effect of the vacancy on the adsorption behavior, for NH₄, the adsorption was found to be proportional to the number of Na atoms in the material, confirming the ion-exchange process. On the contrary, the materials with low vacancy and high Na content showed nominal Cs adsorption capacity. Interestingly, the K adsorption capacity was found to be in between that of the other two ions. This means the ionic size decides the rate of placement into the interstitial sites. For larger ions like Cs, the ease of percolation via the vacancy decides the overall adsorption efficiency.     

全自动固相萃取-气相色谱法测定水中多氯联苯总量

应用全自动固相萃取-气相色谱法测定水中多氯联苯6个Aroclor系列的总量。以特征"指纹峰"为定性依据,用外标法定量。优化的固相萃取条件为:1固相萃取柱为Bond Elut C18柱;2水样体积1.0L;3水样流量10mL·min-1;4洗脱剂为15mL二氯甲烷和15mL乙酸乙酯。用DB-5MS柱分离,电子捕获检测器检测。各多氯联苯的线性范围均为7.0~140.0μg·L-1,检出限均为0.7μg·L-1。以空白样品为基体进行加标回收试验,所得回收率在70.1%~90.0%之间,测定值的相对标准偏差(n=6)在4.3%~6.6%之间。     

固相萃取-高效液相色谱法同时检测畜禽粪便中14种兽药抗生素

研究并优化了同时分析畜禽粪便中14种抗生素(四环素、磺胺、氟喹诺酮和大环内酯类)的加速溶剂萃取参数、固相富集净化程序、以及高效液相色谱分离和检测条件。结果表明,以1%乙酸(pH 2.6)作为流动相,在270 nm的检测波长下,14种抗生素能达到基线分离。3倍信噪比下,四环素、磺胺、氟喹诺酮和大环内酯类抗生素的检出限分别为35～90μg/kg,12～28μg/kg,9～17μg/kg及19μg/kg。加标浓度在1和10μg/g时,畜禽粪便样品经过50%甲醇的柠檬酸盐缓冲溶液提取,HLB固相萃取柱富集净化后,四环素、磺胺、氟喹诺酮和大环内酯类抗生素的回收率分别达到了58%～75%和66%～83%,74%～93%和91%～101%,74%～80%和80%～88%,85%和68%,相对标准偏差分别为6.2%～10.7%和7.8%～13.6,2.6%～10.2%和4.4%～13.2%,6.1%～12.5%和8.3%～14.6%,10.6%和12.3%。采用此方法对辽宁省部分规模化养殖场的猪粪、牛粪和鸡粪样品进行了检测。4类抗生素都有检出,浓度范围分别为0.75～22.34 mg/kg,0.10～1.71 mg/kg,0.38～4.46 mg/kg和0.23～0.35 mg/kg。     

固相萃取-气相色谱法测定茶叶中甲胺磷残留量

茶叶样品经乙酸乙酯提取,上清液于50℃蒸发至近干,加入乙酸乙酯溶解残渣后,经硅胶-石墨化碳混合柱净化。先以乙酸乙酯洗脱去除杂质,再以碱化乙腈洗脱并收集流出液,在50℃蒸发至近干,加乙酸乙酯定容至1mL,供气相色谱分析。采用DB-1701色谱柱分离和火焰光度检测器检测,所得甲胺磷的线性范围为0.010～1.00mg·L-1,方法的检出限(3S/N)为0.005mg·kg-1。在0.010,0.020,0.080 mg·kg-1 3个浓度水平下进行回收试验,甲胺磷的回收率在85.0%～90.9%之间,相对标准偏差(n=6)在2.2%～4.3%之间。     

用于固相萃取的聚乙二醇交联辛烷基、苯基、氨基和氰基固定相

用简单的方法合成了用于固相萃取的填料，填料含辛烷基，苯基，氨基或氰基及聚乙二醇链。这种固定相属于混合功能限进介质。其特点为表面有亲水性和一定程度的疏水性，只吸附少量蛋白质，蛋白质在4种固定相上的吸附量为0．98－3．62mg/g，苯基，氨基和氰基的聚乙二醇交联固定相在pH值4．5对蛋白质的吸附能力最大，而辛烷基聚乙二醇交联固定相在pH值2．5对蛋白质的吸附能力最大，固定相的塔板数能满足固相萃取的要求，含蛋白质的药物样品回收率为92％－115％，合成的固定相可用作生物样品的预处理。     

基于电纺纳米纤维的固相萃取技术

纳米纤维极具优越固相萃取介质的潜质,基于纳米纤维的固相萃取法( Nanofibers based solid phase extraction, NFs-SPE)已成为新兴的样品预处理技术。本文在评述NFs-SPE在食品、环境样品、生物样品等实际样品检测应用的相关研究基础上,提出纳米纤维的分子结构和形态结构与目标物吸附效能之间存在着“结构”-“效应”关系,这将是明确纳米纤维高效吸附目标物的机理的关键突破口。     

Speciation Analysis of Cr(III) and Cr(VI) after Solid Phase Extraction Using Modified Magnetite Nanoparticles

A new solid phase extraction (SPE) method has been developed for the speciation of Cr(III) and Cr(VI). This method is based on the adsorption of Cr(VI) on modified alumina‐coated magnetite nanoparticles (ACMNPs). Total chromium in different samples was determined as Cr(VI) after oxidation of Cr(III) to Cr(VI) using H₂O₂. The chromium concentration has been determined by flame atomic absorption spectrometric (FAAS) technique and amount of Cr(III) was calculated by substracting the concentration of Cr(VI) from total chromium concentration. The effect of parameters such as pH, amount of adsorbent, contact time, sample volume, eluent type, H₂O₂ concentration and cetyltrimethylammonium bromide (CTAB) concentration as modifier on the quantitative recovery of Cr(VI) were investigated. Under the optimal experimental conditions, the preconcentration factor, detection limit, linear range and relative standard deviation (RSD) of Cr(VI) were 140 (for 350 mL of sample solution), 0.083 ng mL^?1, 0.1‐10.0 ng mL^?1 and 4.6% (for 5.0 ng mL^?1, n = 7), respectively. This method avoided the time‐consuming column‐passing process of loading large volume samples in traditional SPE through the rapid isolation of CTAB@ACMNPs with an adscititious magnet. The proposed method was successfully applied to the determination and speciation of chromium in different water and wastewater samples and suitable recoveries were obtained.     

流动注射在线固相萃取预富集毛细管区带电泳测定血浆中的伪麻黄碱

研究了流动注射在线固相萃取与毛细管区带电泳联用系统(FI-SPE-CZE)应用于测定血浆中痕量盐酸伪麻黄碱的方法。通过脱线和在线试样净化、优化CZE分离条件等措施消除了血浆中共存组份的干扰;通过增加固相萃取的进样量、加大场放大电动进样量和柱上堆积的力度等,提高了联用系统的灵敏度。血浆试样沉淀蛋白后可连续进入FI-SPE-CZE系统进行自动的浓缩、分离与分析,检测限为12ng/mL,分析速度达10次/h.应用本方法成功地测定了志愿者口服正常剂量盐酸伪麻黄碱后的血药浓度,并试用于药物动力学的研究。     

溶胶凝胶法制备固相微萃取搅拌棒

采用溶胶凝胶法制备了一种新型PDMS固定相，键合于固相微萃取搅拌棒玻璃表面作为固相萃取固定相。PDMS的一部分以键合的方式与凝胶网络结合，而另外一部分则是被凝胶网络所包埋。由于萃取固定相涂层的厚度在30μm以上，采用多阶程序升温方式对固定相进行老化避免涂层龟裂，制备的萃取固定相耐温达到300℃。     

Fourier Transform Infrared Spectroscopy and Solid Phase Extraction Applied to the Determination of Oil and Grease in Water Matrices

 The solid phase extraction as a solvent-free method for the analysis of oil and grease in waters was studied. The use of a PTFE surface as a solid phase allows the retention of the volatile fraction of oil and grease, and further analysis of carbon–hydrogen bonds using infrared spectroscopy can be done on the surface. Various oils and grease samples were tested: n-hexadecane, n-tetradecane, n-nonadecane, n-docosane, isooctane, diesel oil and gasoline. Temperatures from 25° to 90 °C and a range of heating times were checked for extraction. Precision tests showed relative standard deviation values of around 10% in several samples of the same concentration. Calibration lines of n-hexadecane showed high correlation coefficients from 0.9 to 30 mg/l. Recoveries for the various oils using different calibration lines showed values from 90 to 110%. The method described here is fast and clean, and allows reproducible measurements of oil and grease in water that do not require the use of a solvent. Received March 1, 2001; accepted August 15, 2001; published online July 15, 2002