离子色谱荧光检测法测定废水中痕量2-氨基联苯和4-氨基联苯

采用离子色谱荧光检测法测定废水中的2－氨基联苯（2－ADP）和4－氨基联苯（4－ADP），流动相为1．0mL/min的0．06mol/L NaCl,0.08mol/L HCl,40%(V/V)ACN，分离柱为Dinoex OmniPac PCX-500，该法具有良好的重现性和线性关系，2－ADP和4－ADP的回收率分别为98．5％－101．4％和102．2％－104．0％，检测限分别为0．006mg/L和0．10mg/L。     

环丙沙星荷移反应及荧光光谱性质研究

研究了环丙沙星（CPFX）与电子受体2，3－二氰－5，6－二氯－1，4对苯酯（DDQ）之间的荷移反应。实验结果表明：DDQ与CPFX的荷移反应需在丙酮－甲醇（1：4）介质中进行。两者于40℃水浴中恒温30min即可形成1：1络合物，其荧光发射较CPFX有显著的增强。在0．107．2mg/L浓度范围内，荧光强度与质量浓度呈良好线性关系；其检出限为0．1mg/L。本方法用于片剂中环丙沙星的含量测定，其回收率为96．6％－100．2％；标准偏差为1．3％－2．6％。     

复方维生素B片中主要成分的高效毛细管电泳电化学法检测

采用高效毛细管电泳－电化学检测法同时测定复方维生素B片中的主要成分维生素B1，B12，B6和C的含量；研究了电极电位，运行缓冲溶液的浓度和酸度，电泳电压和进样时间等对电泳的影响，以微铂电极为工作电极，检测电位＋0．5V（vs SCE)，在pH9.0的15mmol/L Tris-1mmol/L H3BO3缓冲溶液中，上述4组分在5min内获得基线分离；维生素B1，B12，B6和C的线性范围分别为2．1mg/L-1.0g/L,6.0mg/L-0.80g/L,1.4mg/L-0.72g/L和0．97mg/L-0.44g/L检出限分别为0．50mg/L,1.0mg/L,,0.65mg/L和0．40mg/L；5次测定峰高的相对标准偏差分别为2．4％，3．0％，3．1％，和2．5％，5次测定的平均回收率分别为99％，102％，98％和100％。     

环境水样中痕量肼的荧光分析

基于在硫酸介质中，肼与罗丹明6G反应，使其荧光增强，建立了一种荧光测定痕量肼的新方法。该方法线性范围2．0－14．0μg/L，检出限为0．62μg/L。可用于环境水样中肼含量的测定，并进行了回收实验，回收率为97％－107％。     

纺织品中游离甲醛的气相色谱分析

建立了测定纺织品中游离甲醛的衍生气相色谱法，方法的测定限为0．0015mg/L，线生关系R^2=0.9999;线性范围为0.0015-40mg/L；相对标准偏差为1．8％和3．3％；回收率为93．2％－101．1％。     

荧光猝灭法测定痕量六价铬

基于六价铬与碘化钾反应生产了单质碘，碘可以使2′，7′－二氯荧光素（DCF）发生荧光猝来，从而间接测定六价铬。六价铬浓度在0．20－2．50μg/25ml范围内，荧光强度差值与六价铬浓度呈线性关系，线性回归方程△F=12．12 0．19，相关系数r=0.9993，检出限为0．10μg/ml。方法简便，灵敏度较高，已用于合成样中六价铬的测定。回收率在100％－103％，结果满意。     

高效液相色谱法测定烟草料液中的糖、甘油和丙二醇

研究了用高效液相色谱法测定烟草料液样品中糖、甘油和丙二醇的方法。烟草料液用Sep-Park-C18固相萃取小柱预分离，以Waters Surar-Pakl钙型阳离子交换柱为固定相，0．05g/L EDTA钙钠水溶液为流动相，示差折光仪为检测器，一次进样测定烟草料液样品中的糖、甘油和丙二醇。线性范围为0．005－5g/L,检测限在1．5－2．5mg/L之间，相对标准偏差为0．89％－1．3％，标准回收率在96．0％－103％之间。方法用于几种烟草料液样品测定，结果令人满意。     

硼氢化钠还原-无色散原子荧光法测定茶叶中汞

建立了汞的硼氢化钠还原－无色散原子荧光测定方法,在最佳条件下,荧光强度与汞浓度在0－25μg/L范围内呈线性关系,相关系数0．9991,检出限0．02μg/L。用拟定的方法测定了茶叶中的汞,回收率为91．6％－98．3％,变异系数不超过5．2％。     

离子色谱法测定柠檬酸、柠檬酸钠中的F^—、CI^—、SO4^2—、C2O4^2—等

利用离子色谱仪,对柠檬酸、柠檬酸钠中的痕量F^-、CI^-、SO4^2－、C2O4^2-等进行测定,采用DIONEX ION PAC AS11－HC分离柱,以电导检测器检测,对淋洗分离条件进行了试验。选择NaOH作淋洗液,0．025－0．050mol/L NaOH做梯度淋洗,可使F^-、CI^-、SO4^2－、C2O4^2-等很好地分离,其中CI^-在0．01－200mg/L,F^-在0．05－200mg/L,SO4^2-在0.05-200mg/L,C2O4^2-在0.1-200mg/L范围内,浓度和响应值有良好的线性关系,检出限分别为F^-0.01mg/L、CI^-0.01mg/L、SO4^2-0.03mg/L、C2O4^2-0.03mg/L,回收率为90％－110％。该方法无需前处理,无基体干扰,可用于柠檬酸、柠檬酸钠中F^-、CI^-、SO4^2－、C2O4^2-的测定。     

过氧化氢-硫唑嘌呤氧化还原反应的研究与应用

研究了硫唑嘌呤水解产物与过氧化还原作用及产物的荧光特性,提出了高灵敏度测定硫唑嘌呤的荧光光度分析新方法。在碱性介质和沸水加热条件下,硫唑嘌呤的水解能被过氧化氢氧化,生成6－嘌呤磺酸钠,该产物不仅具有强的荧光且稳定性好。本体系的激发波长为286nm,发射波长为397nm,荧光强度与硫唑嘌呤的含量在0．025－2．4mg/L范围内呈线性关系,检测限为0．01mg/L。该法已用于片剂中硫唑嘌呤含量的测定。     

胶束毛细管电泳在线推扫技术分离检测猪肉组织中痕量喹诺酮类药物

利用胶束毛细管电泳法结合在线推扫富集技术对组织中残留的痕量环丙沙星、氧氟沙星和恩诺沙星进行了检测, 弥补了毛细管电泳检测灵敏度低的缺点, 大大减化了操作过程, 为动物食品组织中残留的痕量药物检测提供了一种新的简便可靠的方法.     

In vivo pH MEASUREMENT AND IMAGING OF TUMOR TISSUE USING A pH-SENSITIVE FLUORESCENT PROBE (5,6–CARBOXYFLUORESCEIN): INSTRUMENTAL AND EXPERIMENTAL STUDIES

Abstract This study evaluated the effectiveness of dual-wavelength ratio fluorescence imaging using a pH-dependent indicator (5,6–carboxyfluorescein, 5,6–CF) for in vivo pH mapping of tissue. A prototype version of a highly sensitive fluorescence imaging device consisting of a modified xenon lamp, an image-intensified camera and a digital imageprocessing system has been developed. 5,6–Carboxyfluorescein was used because its fluorescence emission increases as a function of pH in the physiological (6.0–7.4) pH range. The ratio of fluorescence intensities obtained with the imaging system has been calibrated using aqueous 5,6–CF standards at various pH values. Because the pH of interstitial fluid of malignant tumors tends to be lower than that of normal tissue and can be depressed by glucose administration, experiments were performed on 10 CDF mice bearing lymphoid leukemia P388 grafted subcutaneously. The range of linearity of the calibration curve was obtained between 5.3 and 6.7 with a measured pK, value of 5.93. Consequently the maximum sensitivity was observed in this range. The calculated pH from ratio images was 6.21 ± 0.12 in tumorous tissue. This value was equivalent to those obtained at the same time using microelectrodes (6.2 ± 0.3).
These experiments showed that a dose of 5 mg/kg 5,6–CF and an excitation power density of 2.5 mW/cm² are sufficient to give a fluorescent pH image of tumors. The limitation of 5,6–CF for the in vivo mapping of tissue results from its low pK_a and consequent range of sensitivity. The advantages of this imaging technique compared to microelectrodes are that it (1) is noninvasive, (2) displays a two-dimensional pH image with high resolution (profile distribution of pH in tissue) and (3) can be used to monitor pH over a few hours.     

Al(III)- CTMAB增敏酸性降解荧光法测定土霉素

The fluorescence characteristics of acid degraded product of oxytetracycline with aluminium(III) in micellar system has been studied.The experiment indicated that oxytetracycline reacts with hydrochloric acid and produces more strong fluorescent species.After CTMAB and aluminium(III)are added in this species,its fluorescence intensity can be enhanced greatly in pH 7.20 Na2HPO4-KH2PO4 buffer solution.Based on this,a new fluorimetric method involving acidic degradation and enhancement by surfactant and aluminium(III)is proposed for the determination of oxytetracyline.The maximum excitation and emission wavelengths are 392nm and 492nm,respectively.The fluorescence intensity is proportional to the concentration of oxytetracycline over the range of 2.01×10-8mol/L～2.10×10-6mol/L with the detection limit of 1.0×10-8 mol/L.The method has been used to the determination of oxytetracycline in tablets with satisfacoty results.     

Separation and determination of epinephrine and dopamine in traditional Chinese medicines by micellar electrokinetic capillary chromatography with laser induced fluorescence detection

A micellar electrokinetic capillary chromatography method with laser-induced fluorescence detection was developed for the analysis of epinephrine and dopamine after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole. The optimum derivatization conditions were: 30 mM sodium borate (pH adjusted to 8.0 with 1.0 M HCl), reaction time 30 min at 60 degrees C. Baseline separation was achieved within 14 min with a running buffer composed of 10 mM sodium borate + 25 mM sodium dodecyl sulfate (pH adjusted to 9.5 with 0.1 M NaOH) and an applied voltage of 15 kV. Good linearity relationships (correlation coefficients: 0.9991 for epinephrine and 0.9985 for dopamine) between peak areas and concentrations of the analytes were obtained. The detection limits and quantification limits for epinephrine and dopamine were 0.0038 mg/L and 0.013 mg/L, and 0.065 mg/L and 0.020 mg/L, respectively. The method was applied to the analysis of the two compounds in two Chinese medicines with recoveries in the range of 92.6-108.7%.     

铁络合光度法测定氧氟沙星和诺氟沙星含量

研究了氧氟沙星、诺氟沙星与Fe(III)在室温下的络合反应.在酸性介质中,氧氟沙星、诺氟沙星与Fe(III)形成的黄色配合物最大吸收波长为436nm;氧氟沙星和诺氟沙星的浓度分别在2.24~192mg/L和8.0~248mg/L范围内与体系的吸光度呈良好的线性关系,其线性回归方程分别为:A=0.009 06+0.005 7 c(c,mg/L;r=0.999 3;氧氟沙星)和A=0.001 23+0.003 04 c(c,mg/L;r=0.999 8;诺氟沙星),方法的检出限分别为0.41和0.76mg/L.对浓度均为64.0mg/L的氧氟沙星和诺氟沙星平行测定11次,其相对标准偏差分别为0.6%和0.8%.应用拟定的方法对氧氟沙星和诺氟沙星药物制剂中主成分的含量进行了测定,回收率在99.7%~104.7%范围内.     

Determination of ciprofloxacin with functionalized cadmium sulfide nanoparticles as a fluorescence probe

A novel assay of ciprofloxacin with a sensitivity at the microgram level is proposed based on the measurement of enhanced fluorescence intensity signals resulting from the interaction of functionalized nano-CdS with ciprofloxacin. The CdS nanoparticles was synthesized by thioacetamide (TAA) and cadmium nitrate (Cd(NO(3))(2)) in the alkaline solution. At pH 7.4, the fluorescence signals of functionalized nano-CdS were greatly enhanced by ciprofloxacin with the increase concentration of ciprofloxacin. Linear relationship can be established between the enhanced fluorescence intensity and ciprofloxacin concentration in the range of (1.25-8.75)x10(-4) mg mL(-1) ((3.77-26.4) x 10(-4)mmol L(-1)) or (8.75-1200) x 10(-4)mg mL(-1) ((26.4-3625) x 10(-4) mmol L(-1)). The limit of detection is 7.64 x 10(-6) mg mL(-1) (2.31 x 10(-5)mmol L(-1)). Based on this, a new direct quantitative determination method for ciprofloxacin in human serum samples without separation of foreign substances was established. The contents of ciprofloxacin in human serum samples were determined with recovery of 95-105% and relative standard deviation (R.S.D.) of 1.5-2.5%. This method was proved to be very sensitive, rapid, simple and tolerance of most interfering substances.     

Spectrophotofluorimetric determination of terbium, europium and samarium with pivaloyltrifluoroacetone and tri-n-octylphosphine oxide in micellar solution of nona-oxyethylene dodecyl ether

The fluorescence intensities of terbium, europium and samarium complexes with several beta-diketone derivatives in the absence and presence of tri-n-octylphosphine oxide (TOPO) in micellar solution of nona-oxyethylene dodecyl ether (BL-9EX) were examined. The spectrophotofluorimetric determination of terbium (1.5-1500 ng/ml) has been investigated with pivaloyltrifluoroacetone (PTA) and TOPO in 0.5% micellar solution (pH 3.8-4.5) of BL-9EX. The excitation and emission wavelengths were 309 and 542 nm, respectively. Europium and samarium could be determined by a similar method.     

A surfactant type fluorescence probe for detecting micellar growth

We report on the detection of micellar growth in anionic, cationic, and catanionic surfactant systems using a novel surfactant type fluorescence probe, sodium 12-(N-dansyl)amino-dodecanate (12-DAN-ADA). The fluorescent group was incorporated in the tail of the surfactant which tethers the fluorescent group deep inside the apolar micellar cores. The fluorescence anisotropy of 12-DAN-ADA was found to be very sensitive for directly detecting the micellar growth in micelles containing oppositely charged surfactants, including cationic CTAB systems and mixed systems of oppositely charged surfactants (DEAB/SDS); in regard to the like charged SDS micellar systems, the sensitivity can be greatly enhanced by addition of a water soluble quencher which quenches the background fluorescence from the equilibrium population of free 12-DAN-ADA.     

Micelle-sensitized constant-energy synchronous fluorescence spectrometry for the simultaneous determination of pyrene, benzo[a]pyrene and perylene.

The use of micellar media in constant-energy synchronous fluorescence spectrometry has been proposed. The influence of some aqueous micellar systems on the determination of pyrene, perylene and benzo[a]pyrene has been investigated. The presence of these micellar systems allows their determination in aqueous media, thus avoiding the use of an organic solvent, and greatly enhances the fluorescence signals. The combination of a constant-energy synchronous scanning technique and a micellar system provided a single spectrum for the simultaneous identification and quantitative determination of the three polycyclic aromatic hydrocarbons (PAHs). Further there was no energy transfer among them, making the measurement simple and fast. A constant-energy difference of 2800 cm(-1) was selected. The analytical characteristics of the proposed method in the presence of anionic micelles of sodium dodecylsulfate (SDS) were studied. The detection limits were at a level of ng ml(-1). Analysis of water samples from two different origins spiked with known amount of pyrene, perylene and benzo[a]pyrene also gave satisfactory results, and total average recoveries were greater than 97.1%.     

Determination of nicotinyl pesticide residues in vegetables by micellar electrokinetic capillary chromatography with quantum dot indirect laser-induced fluorescence

A new assay was developed by use of micellar electrokinetic capillary chromatography with indirect LIF fluorescence for the determination of thiamethoxam, acetamiprid, and imidacloprid residues in vegetables, in which the cadmium telluride quantum dots (QDs) synthesized in aqueous phase were used as fluorescent background substance and their excitation and emission wavelengths matched with LIF detector by engineering their size. The factors that affected the peak height and the resolution were optimized. The running buffer was composed of 4.4 μM cadmium telluride QDs as fluorescent background substance, 40 mM borate and 60 mM SDS, and its pH was adjusted to 8.0. The separation voltage was 25 kV. Under the optimum conditions, the detection limits were 0.05, 0.01, and 0.009 mg/kg; the linear dynamic ranges were 0.5-30, 0.1-30, and 0.1-30 mg/L; and the average recoveries of spiked samples were 72.0-101.2, 74.0-106.7, and 77.8-105.1% for thiamethoxam, acetamiprid, and imidacloprid, respectively. The assay can meet the requirement of maximum residue limits to these three pesticides in the regulations of European Union and Japan, and has been applied for determining their residues in vegetables.