衍生-固相萃取联用分光光度法测定甲醛及应用

建立了衍生-固相萃取联用结合分光光度法检测复杂样品中甲醛的分析方法。以乙酰丙酮为衍生试剂对甲醛进行衍生,用C18柱固相萃取富集乙酰丙酮甲醛衍生物,优化最佳条件为:上样酸度pH 5.6,上样体积10.0mL,1.5mL甲醇洗脱,洗脱溶液于波长416nm测定吸光度。方法线性范围0.01～2.0mg/L(r=0.9994),检出限0.002mg/L。用该方法分别测定了啤酒、菇类样品中的甲醛,加入回收率在85.3%到100.8%之间。方法简单,灵敏度高,样品测定结果可靠。     

微晶酚酞分散固相萃取-分光光度法测定痕量亚硝酸根

研究了微晶酚酞固相萃取-分光光度法测定痕量亚硝酸根。高浓度的酚酞乙醇溶液滴入水中后,酚酞会析出大量微晶,对疏水性物质具有很强的吸附萃取能力,据此建立了痕量亚硝酸根测定的新方法。详细考察了影响萃取富集效率的多种因素,在最佳实验条件下,该方法的线性范围为1.0~160μg/L(r=0.9999),检出限为0.29μg/L。方法已成功应用于实际水样分析,加标回收率在98.1%~103.6%之间,相对标准偏差为1.9%~3.4%。     

固相萃取-高效液相色谱法测定人体尿液中邻苯二甲酸酯及其代谢物

建立了同时测定人体尿液中邻苯二甲酸酯及其代谢物的分析方法.对洗脱剂种类、洗脱体积、洗脱流速等影响因素进行考察,确定了最佳洗脱剂及洗脱体积为2mL乙腈、2mL乙酸乙酯和1mL乙醚-正己烷(1:19,V/V),洗脱流速1mL/min.在最优化的固相萃取-液相色谱条件下测定5种邻苯二甲酸酯及其5种相应的单酯代谢物,线性范围为...     

固相萃取光度法测定饮用水中挥发酚的研究

研究了用Waters Sep-Park-C18小柱固相萃取光度法测定饮用水中挥发酚的方法。水样中经水汽蒸馏分离后的挥发酚,用4－氨基安替比林显色,显色产物可用C18固相萃小柱萃取、乙醇洗脱后用分光光度法测定。方法污染小,操作简便,便于批量样品处理,用于饮用水中挥发酚的测定,结果令人满意。     

铬络合物的固相萃取富集和分光光度法测定

本文提出了用聚乙烯粉末固相萃取铬络合物的方法。在强酸性介质中，Ｃｒ（Ⅵ）与二苯碳酰二肼发生氧化还原反应，反应产物能结合生成稳定的络合物。     

固相分光光度法测定水中痕量磷

固相分光光度法是一种简单、快速、灵敏的新型痕量分析手段。本文首次提出利用氯型阴离子交换树脂做固体吸附剂,采用“模型压片法”测定水中痕量磷。结果令人满意。     

固相萃取-顺序注射分光光度法快速测定微生物菌落中的麦白霉素

在顺序注射系统中引入C18固相萃取柱进行生米卡链霉菌菌落样品的纯化富集,建立了快速测定菌落中麦白霉素的分光光度法。用超声波破碎菌落细胞后,将样品溶液通过固相萃取柱,用少量甲醇洗脱吸附在C18微珠上的麦白霉素,232 nm检测。进样量为2 ml,洗脱液体积为100μL,麦白霉素的富集倍率为14;线性范围为0.1~10μg/mL,检出限为0.02μg/mL,RSD为2.5%(0.5μg/mL,n=7)。菌落样品中麦白霉素的加标回收率为96%~100%。     

固相分光光度法测定鱼体中稀土总量

随着稀土进入水环境的数量不断增加，对水生态环境带来潜在影响，并可能通过食物链（如鱼等）影响人体健康．因此，鱼体中稀土含量的测定，对全面了解水生环境中稀土元素的分布有重要意义．本文用树脂做固相吸附剂，模型压片，５－Ｂｒ－ＰＡＤＡＰ光度法测定鱼体中稀土总...     

分光光度法快速测定食品中亚硝酸盐的含量

对分光光度法测定食品中亚硝酸盐含量的方法做了两点改进:其一,采用超声提取法,提取时间较短;其二,采用小体积条件下操作,使整个分析过程快速化,适用现场执法快速检测。本方法的准确性和精密度与国家标准方法的要求相符。     

磁固相萃取联合荧光法测定生物样品中的卡维地洛

该文采用Fe₃O₄纳米材料、1,3,5-三甲基间苯三酚（Tp）和联苯胺（BD）,通过溶剂热法制备了Fe₃O₄@COF（TpBD）复合材料,并以其作为吸附剂,建立了一种磁固相萃取联合荧光分光光度法测定生物样品中卡维地洛（CAR）的新方法。通过透射电镜（TEM）、X射线衍射（XRD）、傅里叶红外光谱（FT－IR）、振动样品磁强仪（VSM）及比表面和孔隙度分析仪等测试手段对吸附剂进行了表征。并对溶液pH值、吸附剂用量、萃取时间、解吸剂及其体积和解吸时间等实验参数进行了优化。在优化的实验条件下,方法的线性范围为1～100ng/mL,检出限（S/N=3）和定量限（S/N=10）分别为0.19ng/mL和0.63ng/mL,在低、中、高3个加标水平下的回收率为95.9%～98.7%,该方法回收率和灵敏度高、稳定性好,可应用于尿样和血样中卡维地洛的分析。     

对磺酸基苯亚甲基硫代若丹宁固相萃取光度法测定金的研究

用文献[4]合成的新试剂对磺酸基苯亚甲基硫代若丹宁(SBDTR),研究了SBDTR与金的显色反应。在HCl介质中,乳化剂-OP存在下,SBDTR与金反应生成2∶1稳定络合物,络合物的λmax=540 nm,ε=1.05×105L.mol-1.cm-1,金量在0.1~20μg/10 mL内符合比尔定律,样中的金用TBP萃淋树脂固相萃取柱分离和富集后用该方法测定,方法相对标准偏差为2.2%~3.6%,标准回收率为96%~105%。     

Solid Phase Extraction and Spectrophotometric Determination of Mercury in Tobacco and Tobacco Additives with p-Sulfobenzylidenerhodanine as Chromogenic Reagent

A highly sensitive, selective and rapid method for the determination of mercury based on the reaction of mercury(II) with p-sulfobenzylidenerhodanine (SBDR) and the solid phase extraction of the colored chelate with a C₁₈ cartridge has been developed. In the presence of pH 3.8 acetate buffer solution and Tween-80 medium, SBDR reacts with mercury to form a red chelate of a molar ratio of 1:2 (mercury to SBDR). This chelate was enriched by solid phase extraction with a C₁₈ cartridge and eluted from the cartridge with ethanol (containing 5% acetic acid). The enrichment factor of 50 was achieved. In the ethanol medium, the molar absorptivity of the chelate is 1.28×10⁵L·mol^–1·cm^–1 at 545nm. Beers law is obeyed in the range of 0.011.2µgmL^–1 in the measured solution. The relative standard deviation for eleven replicate samples of 0.01µgmL^–1 level is 1.52%. This method can be applied to the determination of mercury in tobacco and tobacco additives with good results.     

8-羟基喹哪啶固相萃取光度法测定水样中的铁

研究了8-羟基喹哪啶与铁的显色反应,在pH为8．0的氯化氨-氨水缓冲介质中,在十六烷基三甲基溴化铵(CTMAB)存在下,8-羟基喹哪啶与铁反应生成3：1稳定的蓝紫色络合物,该络合物可被Waters Sep-Park-C18固相萃取小柱萃取,用乙醇洗脱后用光度法测定,络合物λmax=600nm。在此波长下其它金属离子的络合物无光吸收,对铁选择性很好,铁含量在0-5mg/L内符合比尔定律,方法用于水样中痕量铁的测定,结果令人满意。     

固相膜萃取-气相色谱法测定尿液和血液中的毒鼠强

研究了固相膜萃取-气相色谱测定尿液、血液中毒鼠强的方法。样品经固相膜吸附,然后经溶剂洗脱、蒸发浓缩定容,最后进行气相色谱分析。该法操作简便、结果准确可靠,能有效排除杂质的干扰。毒鼠强在尿液和血液中的平均回收率分别为86.4%和83.4%,检出限分别为0.1 ng和2 ng。     

Activated carbon/diatomite-based magnetic nanocomposites for magnetic solid-phase extraction of S-phenylmercapturic acid from human urine

In this study, activated carbon/diatomite-based magnetic nancomposites (denoted as AC/DBMNs) were synthesized and applied as an adsorbent for magnetic solid-phase extraction of S-phenylmercapturic acid (S-PMA) from human urine prior to high-performance liquid chromatography. The surface morphologies and structures of AC/DBMNs were characterized by Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller surface area, vibrating sample magnetometer and ζ-potential measurements. The experimental parameters including sample volume, sample pH, adsorbent amount, extraction time, elution solvent and desorption time were investigated in detail. Under the optimum conditions, the method exhibited good linearity (r > 0.9993) within the concentration ranges of 0.03–1.0 mg/L. Moreover, the limits of detection and quantification were 0.01 and 0.03 mg/L, respectively. The enrichment factor was 5, and good recoveries (88.9–97.3%) with relative standard deviations in the range of 5.6–6.8% (n = 6) for inter-day and 6.3–8.1% (n = 6) for intra-day were achieved. The developed method was successfully applied to the analysis of S-PMA in urine samples. In addition, this accurate and sensitive method has great potential to be applied in the early screening and clinical diagnosis of the workers exposed to benzene.     

Analysis of human urine metabolites using SPE and NMR spectroscopy

Nuclear magnetic resonance (NMR) spectroscopic analysis of metabonome/metabolome has widespread applications in biomedical science researches. However, most of NMR resonances for urinary metabolites remain to be fully assigned. In the present study, human urine samples from two healthy volunteers were pre-treated with C18 solid-phase extraction and the resultant 5 sub-fractions were subjected to one- and two-dimensional NMR studies, including 1H J-Resolved, 1H-1H COSY, 1H-1H TOCSY, 1H-13C HSQC, and HMBC 2D NMR. More than 70 low molecular weight metabolites were identified, and complete assignments of 1H and 13C resonances including many complex coupled spin systems were obtained.     

2-(2-喹啉偶氮)-5-二乙氨基苯甲酸固相萃取光度法测定环境水样中的镍

用2－（2－喹啉偶氮）－5－二乙氨基苯甲酸（QADEAB）与镍的显色反应及Waters Porapak^R Sep-Park固术萃取小柱对显色络合物的固相萃取,建立了测定水样中μg/L级镍的新方法。水样中的镍在pH=8.0的硼酸－磷酸二氢钾缓冲介质中和Tween 80存在下与QADEAB反应生成2：1稳定有色络合物,该络合物可用Waters Porapak^R Sep-Park固相萃取小柱富集,用乙醇洗脱后用光度法测定,可测定水样中μg/L级的镍。方法用于几种环境水样分析,结果令人满意。     

Quantification of five neonicotinoids in human urine by modified QuEChERS with isotope dilution mass spectrometry: a preliminary study for the development of certified reference material

ABSTRACT

A study for the quantification method of neonicotinoid pesticides (Neos) in human urine that aims to develop the certified reference material (CRM) in the future was carried out. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on dispersive solid phase extraction (d-SPE) with isotope dilution mass spectrometry (IDMS) was evaluated for the quantification of five Neos (acetamiprid, dinotefuran, imidacloprid, thiacloprid and thiamethoxam) in human urine control by optimisation of the extraction solvent, and the type and amount of d-SPE material. Two types of human urine controls (sample A and B) containing 5 μg/kg and/or 25 μg/kg of Neos were prepared and employed for this study. The results of spike test using sample A (2 mL) obtained by modified QuEChERS method with acetone extraction (10 mL) and d-SPE using a strong cation exchanger (silica gel modified with benzenesulphonic acid phase, SCX) 500 mg were as follows: 97.8%–103.1% for 5 μg/kg and 97.2%–102.7% for 25 μg/kg (described as percentage by the quantification results of IDMS relative to the spiked amount of pesticides). These results were comparable to those by SPE cartridge method using SCX functionalised hydrophilic styrene divinylbenzene (PCX). The repeatabilities of the analyses, represented as relative standard deviations, were also comparable for spike level 5 μg/kg and 25 μg/kg of Neos: 0.1%–7.2% for modified QuEChERS with IDMS and 0.2%–5.6% for PCX cartridge method. The results of spike test using sample B for a spike level 5 μg/kg were 96.0%–100.6%. These results indicate that modified QuEChERS method with IDMS can be used for the development of certified reference material and has the potential to use for the quantification of Neos in real human urine.     

Quantitative determination of trace phenazopyridine in human urine samples by hyphenation of dispersive solid‐phase extraction and liquid‐phase microextraction followed by gas chromatography/mass spectrometry analysis

Magnetic dispersive solid‐phase extraction followed by dispersive liquid?liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid‐phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene‐pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid?liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray analysis. Calibration curve was linear in the range of 0.5?250 ng/mL (R² = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra‐ and interday precisions (RSD%, n = 3) of the method were in the range of 4.6?5.4% and 4.0?5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0?89.0%.