高效液相色谱法测定猪组织中咪唑苯脲残留研究

建立了高效液相色谱(HPLC)测定猪可食性组织中咪唑苯脲残留的方法。猪组织经β-葡萄糖苷酶水解后,用1 mol/L盐酸提取,再用正己烷-异戊醇(3:2, v/v)混合溶剂萃取净化。以乙腈和0.0075 mol/L戊烷磺酸钠水溶液(含0.1%三乙胺,pH 3.0)作为流动相,经C18反相色谱柱分离后用紫外检测器检测。结果表明: 该方法在咪唑苯脲含量为10～10000 μg/L范围内呈现良好的线性关系,相关系数大于0.999;空白组织中加标样品的检出限(LOD)为10 μg/kg,定量限(LOQ)为20 μg/kg。在定量限、最高残留限量(MRL)、2倍MRL添加水平下,不同组织的平均回收率为80.04%～110.32%,相对标准偏差为0.82%～10.00%。表明该检测方法简单、灵敏,适用于猪组织中咪唑苯脲残留的定量检测。     

高效液相色谱-柱后化学发光法检测人体尿液中的卡托普利

在酸性条件下,Ce?氧化Ru(bipy)32+生成Ru(bipy)33+,同时氧化卡托普利生成二硫化物中间活性态([RS-SR]*),Ru(bipy)33+和二硫化物中间活性态之间相互反应产生强烈的化学发光。基于此,根据发光试剂Ru(bipy)32+水溶性好、试剂稳定等特点,将其加入到流动相中,通过高效液相色谱分离,建立了柱后化学发光快速灵敏检测卡托普利的方法。在以甲醇-0.01mol/L KH2PO4-1g/L Ru(bipy)32+(80∶20∶2,V/V)为流动相,流速为0.9mL/min,8.0×10-4 mol/L Ce?的优化实验条件下,方法的线性范围为2.0×10-7～1.0×10-4 mol/L(R2=0.9988),检出限为6.0×10-8 mol/L(S/N=3),并对1×10-5 mol/L卡托普利平行测定11次,相对标准偏差(RSD)为1.8%。将本方法用于人体尿液中卡托普利含量的测定,结果令人满意。结合化学发光光谱,对该体系发光机理进行了探讨。     

Simultaneous determination of trace of loxacin, ciprofloxacin, and sparfloxacin by micelle TLC-fluorimetry

The method of simultaneous determination of ofloxacin (OFLX), ciproflxacin (CPLX), and sparfloxacin (SPLX) by thin-layer chromatography is established, with micelle solutions as mobile phases. It is found that the optimum molar ratio of sodium dodecyl sulfate (SDS) to ethylene diamine tetraacetic acid is 0.01:0.1. On the polyamide thin-layer sheet, OFLX, CPLX, and SPLX are separated from each other, and the corresponding Rf values are 0.72, 0.55, and 0.32, respectively. The fluorescence spots are scanned with a spectrodensitometer at the excitation wavelength of 282 nm. The cut-off filter is set at 400 nm. The detection limits are 2 x 10(-6) mol/L for OFLX, 1.5 x 10(-6) mol/L for CPLX, and 1.6 x 10(-6) mol/L for SPLX, and the respective linear ranges correspondingly fell in the concentration of 1 x 10(-5) to 4 x 10(-4) mol/L for OFLX, 1 x 10(-5) to 4.5 x 10(-4) mol/L for CPLX, and 1 x 10(-5) to 4.2 x 10(-4) mol/L for SPLX. For all the three components, the relative standard deviations are in the range of 1.12-5.82%, and the recoveries are found to be 96.7-104.2% in urine and serum samples.     

离子色谱法分离分析Cr(Ⅲ)齐聚物

 用离子交换分析柱和二极管阵列检测器建立了水溶液中三价铬离子 [Cr(Ⅲ ) ]齐聚物的分析方法 ,研究了检测条件、流动相、离子强度对分析的影响 ,优化了分析条件。以 3mol/LNaClO4(内含 0 0 3mol/LHClO4)为流动相 ,在TSK GelSP 5PW离子交换分析柱 ( 75mm× 7 5mmi d ,10 μm)上对制备样品中的Cr(Ⅲ )齐聚物进行分离 ,以 2 0 0nm波长检测。该方法简便、快速 ,重复性好 ,10min内便可完成对制备样品中 3种Cr(Ⅲ )齐聚物的色谱分离。用该方法分析了各种制备条件下Cr(Ⅲ )齐聚物的含量 ,优化了制备条件。     

微透析取样-流动注射电化学检测测定表柔比星与牛血清白蛋白体外结合参数

建立了微透析取样-流动注射电化学检测法测定表柔比星与牛血清白蛋白体外结合参数的方法。流动相为pH 3.0的0.1 mol/L H3PO4-NaH2PO4缓冲液(含3.4×10﹣5mol/L Na2EDTA),流速为0.3 mL/min。电化学检测的工作电极为玻碳电极,工作电位为0.52V。表柔比星浓度在5.0×10-5～5.0×10-7 mol/L范围内与峰电流呈良好的线性关系,其相关系数为0.9997,检出限为2.0×10-7mol/L。结合微透析取样,实现了对表柔比星与牛血清白蛋白结合参数的测定。表柔比星与牛血清白蛋白的体外结合符合Scatchard曲线,结合常数和结合位点数分别为2.41×104L/mol和4.02。     

柱前衍生-反相高效液相色谱法测定人血白蛋白中辛酸钠含量

建立了柱前衍生-反相高效液相色谱法测定人血白蛋白中辛酸钠含量的方法。用正己烷萃取人血白蛋白中的辛酸钠,与ω-溴苯乙酮和18-冠-6醚在50℃反应30min,然后用甲醇-水(75∶25,V/V)于Nova-ParkC18柱(150mm×3.9mm,4μm)上分离,在262nm检测衍生物,流速为1.0mL/min,庚酸为内标。辛酸和庚酸的萃取率可分别达到98.2%和97.9%,RSD小于0.9%。方法的线性范围为9.00×10-4～1.44×10-2mol/L(r=0.9995),平均加样回收率为99.7%,RSD≤0.9%。本方法准确、重现性好,可用于人血白蛋白中辛酸钠含量的测定。     

固相萃取–高效液相色谱法测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的残留量

建立了测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的固相萃取–高效液相色谱法。样品以0.1 mol/L的盐酸溶液为提取剂,经C18固相萃取柱净化处理,以乙腈–10 mmol/L乙酸铵水溶液(体积比25∶75)为流动相,Tech Mate C_(18)–ST色谱柱分离,4-氯苯氧乙酸钠和6-苄基腺嘌呤的紫外检测波长分别为228 nm和267 nm,色谱峰面积外标法定量。在0.50~100.00 mg/L浓度范围内,4-氯苯氧乙酸钠的相关系数为0.999 8,精密度在1.3%~8.2%之间(n=6),回收率在103.1%~109.0%之间;在0.05~10 mg/L浓度范围内,6-苄基腺嘌呤相关系数为0.999 9,精密度在0.9%~3.8%之间(n=6),回收率在88.0%~95.4%之间。4-氯苯氧乙酸钠和6-苄基腺嘌呤的检出限(S/N=3)分别为0.24,0.02 mg/kg。该法可以同时完成豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的分析检测。     

邻苯二甲醛-尿素柱前衍生高效液相色谱法快速检测枸杞中牛磺酸

干枸杞经粉碎、匀浆、离心后,通过阳离子交换柱脱去样品中其它氨基酸,再通过Ｚｏｒｂａｘ－Ｃ８柱进行柱前衍生分离。衍生剂：Ａ．４％ＯＰＡ甲醇溶液;Ｂ．尿素∶磷酸钠盐缓冲液（ｐＨ６．８）＝１∶３（Ｗ／Ｖ）。流动相：甲醇∶０．０１ｍｏｌ／Ｌ乙酸钠溶液（ｐＨ６．８）＝３５∶６５（Ｖ／Ｖ）。紫外检测波长３３０ｎｍ。牛磺酸浓度在０．１～１．０ｍｍｏｌ／Ｌ范围内可被定量测定。回收率可达１００．３１％±１．９８％,变异系数（ＣＶ）为１．９４％。     

纳米纤维固相萃取-高效液相色谱法测定血浆中的5-羟色胺

基于纳米纤维的富集作用,建立了血浆中5-羟色胺(5-HT)的柱前衍生高效液相色谱-电化学检测(HPLC-ECD)分析方法.用10%(v/v)高氯酸溶液沉淀血浆蛋白,离心后取上清液,用0.1 mol/L 的四苯硼酸钠溶液调节pH值至8.5,加入衍生剂邻苯二甲醛溶液于30 ℃衍生4 min,经纳米纤维固相萃取柱净化富集后,...     

Reversed phase HPLC determination of titanium(IV) and iron(III) with sodium 1,2-dihydroxybenzene-3,5-disulfonic acid

A highly sensitive method has been developed for the determination of titanium(IV) and iron(III) by ion-pair reversed phase liquid chromatography using sodium 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron) as a precolumn chelating reagent. The metal - Tiron chelates were separated on a C₁₈ (ODS) column; the mobile phase was a 2:8 (v/v) mixture of acetonitrile and acetate buffer (0.04 mol/L, pH 6.2) containing 2.0 × 10^?3 mol/L Tiron, 0.04 mol/L tetrabutylammonium bromide, and 0.1 mol/L potassium nitrate. The detection limits for titanium(IV) and iron(III) are 0.5 and 2.0 μg/L, respectively. The method has been applied to the simultaneous determination of titanium(IV) and iron(III) in river water samples and has furnished highly precise results.     

Exclusion chromatography of polypropylenamine dendrimers

Size-exclusion chromatography of polypropylenamine (POPAM) dendrimers is investigated. The nitrile-terminated half-generations can be analysed on polystyrene-divinylbenzene-based column packings using tetrahydrofuran as a mobile phase. Several basic and acidic aqueous phase systems were compared for exclusion chromatography of POPAM-amine dendrimers. The optimum system consists of a reversed-phase silica stationary phase deactivated by tetraazacyclotetradecane and a mobile phase of 0.25 M formic acid at 60°C. Several by-products were identified by thermospray mass spectrometric detection.     

Direct determination of amino acids by pressurized capillary electrochromatography with chemiluminescence detection

A pressurized CEC (pCEC) coupled with on-column chemiluminescence (CL) detection was developed for direct determination of amino acids, which was based on the principle of an enhanced effect of Cu(II)-amino acid complexes on the CL reaction between luminol and hydrogen peroxide in alkaline solution. The effects of some important factors on pCEC separation and CL intensity were systemically investigated. Baseline separation of amino acids including L-histidine (L-His), L-threonine (L-Thr), and L-tyrosine (L-Tyr) was achieved by using a monolithic column with a mobile phase of 5.0x10(-3) mol/L phosphate buffer at pH 8.0 that contained 25% v/v methanol and 5.0x10(-4) mol/L luminol and 1.0x10(-5) mol/L Cu(II) at an applied voltage of -5 kV. The calibration curves of the analytes by plotting the peak height against corresponding concentration were linear over the range of 3.2x10(-6)-3.2x10(-4) mol/L for L-His, 4.1x10(-6)-4.1x10(-4) mol/L for L-Thr, and 6.0x10(-7)-3.0x10(-4) mol/L for L-Tyr. The LODs for L-His, L-Thr, and L-Tyr were 6.4x10(-7), 8.4x10(-7), and 3.0x10(-7) mol/L (S/N = 2), respectively. The proposed method was applied to the analysis of amino acid injection sample with satisfactory results. Mean recoveries for three amino acids were from 84.3 to 89.6%.     

Determination of bavachin and isobavachalcone in Fructus Psoraleae by high-performance liquid chromatography with electrochemical detection

A simple, sensitive and selective method of high-performance liquid chromatography with electrochemical detection (HPLC-ECD) has been developed for simultaneous determination of bavachin and isobavachalcone in Fructus Psoraleae. At optimized conditions, bavachin and isobavachalcone could be well separated within 15 min at a detection potential of +0.80 V with 0.03 mol/L acetate buffer solution (pH 5.17)/acetonitrile (2:3, v/v) as the mobile phase. The relationships between peak areas and concentrations were linear from 8.26 × 10(-7) to 1.21 × 10(-4) mol/L for bavachin, and from 1.01 × 10(-8) to 1.61 × 10(-4) mol/L for isobavachalcone, respectively. The method offered excellent linearity with regression coefficient R(2) >0.995. The method presented detection limits (S/N = 3) of 8.81 × 10(-9) mol/L for bavachin and 1.17 × 10(-10) mol/L for isobavachalcone. It indicates that the sensitivity of electrochemical detection is ten times higher than that of diode array detection (DAD). The mean recoveries around 98% with a relative standard deviation less than 3.1% for the two analytes have been obtained. The proposed separation and detection procedures were successfully applied to the simultaneous determination of bavachin and isobavachalcone in traditional Chinese medicine.     

Inductively coupled plasma atomic emission spectroscopic determination of rare earth elements in geological samples after preconcentration by countercurrent chromatography—Part II

This paper directly links up with Part I [Spectrochim. Acta 48B, 1365 (1993)] which treats the first application of countercurrent chromatography (CCC) for pre-separation of rare earth elements (REE) in rocks. The rapid and reliable separation and pre-concentration of “light” REE and Y can be achieved using a system of 0.5 mol/l di-2-ethylhexylphosphoric acid (D2EHPA) in n-decane-hydrochloric acid of different concentrations and a planetary centrifuge as a CCC device. However, Tm, Yb and Lu are partially retained in the stationary phase. Comparative data is presented on three other two-phase liquid systems containing trioctylphosphine oxide (TOPO); D2EHPA and TOPO mixtures and diphenyl(dibutylcarbamoylmethylphosphine)oxide (Ph₂-Bu₂) as extractants in terms of their ability for whole REE group complete isolation from the rock constituents. The partial losses of “light” REE (La and Ce) occurred in the system of 0.1 mol/l solution of TOPO in isobutylmethylketone (IBMK) (stationary phase)-1 mol/l NH₄NO₃-6 mol/l HCl aqueous solutions (mobile phase). Complete isolution of the entire REE group can be reached in two systems: 0.3 mol/l D2EHPA + 0.02 ml/l TOPO in the solvents mixture (3:1) of n-decane + IBMK, respectively (stationary phase)-1 mol/l NH₄NO₃-6 mol/l HCl aqueous solution (mobile phase), and 1.0 mol/l Ph₂-Bu₂ solution in chloroform (stationary phase)-3 mol/l HNO₃ aqueous solution (mobile phase). The D2EHPA + TOPO mixture is recommended as more economic and accessible.     

Simultaneous Determination of Palladium and Platinum by On‐Line Enrichment Followed by Rapid Column High Performance Liquid Chromatography

In this paper, a new method for the simultaneous determination of palladium and platinum ions was developed using a rapid column high performance liquid chromatograph equipped with an on‐line enrichment technique. The palladium and platinum ions were pre‐column derivatized with 5‐(p‐aminobenzylidene)‐thiorhodanine (ABTR) to form colored chelates. The Pd‐ABTR, Pt‐ABTR chelates can be absorbed onto the front of an enrichment column when they were injected into the injector and sent to the enrichment column [ZORBAX Stable Bound, 4.6 × 10 mm, 1.8 μm] with a buffer solution of 0.05 mol/L sodium acetate‐acetic acid buffer solution (pH 3.5) as mobile phase. After the enrichment had finished, by switching the six‐ports switching valve, the retained chelates were back‐flushed by mobile phase and traveled towards the analytical column. These chelates separation on the analytical column [ZORBAX Stable Bound, 4.6 × 50 mm, 1.8 μm] was satisfactory with 65% methanol (containing 0.05 mol/L of pH 3.5 sodium acetate‐acetic acid buffer salt and 0.01 mol/L of tritonX‐100) as mobile phase. The palladium and platinum were separated completely within 2 min. The detection limits (S/N = 3) of palladium and platinum are 1.4 ng/L and 1.6 ng/L, respectively. This method was applied to the determination of palladium and platinum in water and urine samples with good results.     

逆流色谱分离镅(Ⅲ)和铕(Ⅲ)的研究

选择0.1 mol/L NaC lO4为流动相,以二氯苯基二硫代膦酸的二甲苯溶液为固定相,研究了萃取剂浓度、流动相pH及流动相流率对逆流色谱(CCC)分离Am3 和Eu3 效果的影响。结果表明,在实验条件下,两者的分离系数随着固定相中的萃取剂浓度增加、流动相的pH升高而增大;降低流动相流率后可明显改善分离效果。通过改变分离条件,Am3 和Eu3 可基本上实现相互分离,两者间的分离系数和分离效率分别达到2.87和0.74。     

Determination of ng rivanol in human plasma by SPE-HPLC method

A high-performance liquid chromatography assay is described for the determination of rivanol in human plasma. Solid-phase extraction cartridges are used to extract plasma samples. Separation is done by using a C18 column. The mobile phase is a mixture of methanol-0.05% sodium dodecylsulfonate (70:30, v/v, pH 3), with the flow rate at 1.0 mL/min. UV detection of rivanol is at 272 nm. The calibration curve is linear in the concentration range of 1x10(-8) mol/L to 1x10(-5) mol/L with linear correlation coefficient r equal to 0.9998. The limit of detection for the assay is 3x10(-9) mol/L, corresponding to 1.1 ng/mL. Precision, expressed as the within- and between-day coefficient of variation, is 3.3-8.1% and 4.1-9.5%, respectively, at plasma control samples of 5x10(-8), 5x10(-7), and 5x10(-6) mol/L. And the recovery ranges from 94.8% to 107.2%. The selectivity of the method is confirmed. Plasma samples are stable for at least 15 days if they are stored lightproof at -20 degrees C. This method is simple, sensitive, and accurate, and it allows for the determination ng rivanol in human plasma. It could be applied to assessing its plasma level in women receiving an intra-amniotic injection of rivanol.     

On-line coupling of pressurized capillary electrochromatography with end-column amperometric detection for analysis of estrogens

An improved technique, pressurized capillary electrochromatography (pCEC) coupling with end-column amperometric detection (AD), was developed and used for the separation and determination of estrogens. The effects of pH value, composition of mobile phase, concentration of the surfactant sodium dodecyl sulfate (SDS) and applied voltage on separation were investigated. The electrochemical oxidation of diethylstilbestrol (DES), dienestrol (DE), and hexestrol (HEX) could be reliably monitored with a carbon electrode at 0.9 V (vs. Ag/AgCl). The pCEC analyses were performed on a capillary separation column packed with 3 microm C18 particles with an acetonitrile/water (31%: 69%) mobile phase containing Tris buffer (5 mmol/L, pH 4.5) and 4 mmol/L SDS. High voltage up to 12 kV reduced the retention time dramatically and still provided a baseline resolution. In addition, supplementary pressure prevented bubble formation and provided reliability and reproducibility of the pCEC performance. The detection limits for the three estrogens ranged from 1.2 to 2.2x10(-7) mol/L, about 10 20-fold lower than those obtained with pCEC-UV detection. To evaluate the feasibility and reliability of this system, the proposed pCEC-AD method was further demonstrated with fish muscle samples spiked with estrogens.     

Direct determination of nitrite traces in high ionic-strength samples by electrostatic ion chromatography using diluted acid solutions as eluent

An ion-chromatographic (IC) system with high selectivity for separation of nitrite is described. It is analogous to the EIC (electrostatic IC) previously reported and was established using 3-(N,N-dimethylstearylammonio)propanesulfonate (C23H49NO3S, a sulfobetaine type of zwitterionic surfactants) as the stationary phase and dilute aqueous HCl solutions as the mobile phase. Five inorganic anions, sulfate, chloride, bromide, nitrate, and nitrite were chosen as the model analytes and were analyzed using this EIC system. Sulfate was always eluted first, followed by chloride, bromide and nitrate. Nitrite, however, could be eluted either before or after nitrate, depending on the concentration of HCl in the eluent. An elution order nitrate< nitrite was always obtained simply by using >3 mmol L(-1) HCl as the eluent. For nitrite the detection limit was better than 2.1 x 10(-7) mol L(-1) (100 microL sample injection volume, S/N=3, UV at 210 nm). Bromide and nitrate could also be separated under these HPLC conditions. The detection limit for bromide was 7.2 x 10(-8) mol L(-1) and for nitrate 6.5 x 10(-8) mol L(-1). Both nitrite and nitrate in real seawater samples were successfully determined with direct sample injection using this EIC system.