同步荧光法测定大鼠尿液中色氨酸、异黄蝶呤和黄蝶呤

本文建立了大鼠尿液中色氨酸、异黄蝶呤和黄蝶呤的同步荧光分析方法,在KH2PO4-NaOH缓冲溶液(pH=8.0)中,波长差(△λ)为70nm的条件下进行同步荧光扫描,分别在275nm、325nm和400nm处测定色氨酸、异黄蝶呤和黄蝶呤。三种物质的仪器检出限分别为2.73ng/mL、0.52ng/mL和0.94ng/mL,对膀胱癌模型组和对照组的大鼠尿样进行了加标回收实验,平均回收率在80.5%~98.0%之间,相对标准偏差为0.62%~2.48%。方法已应用于大鼠尿样中色氨酸、异黄蝶呤和黄蝶呤的测定。     

偏最小二乘-同步荧光法测定人尿中黄蝶呤

建立了人尿中黄蝶呤含量测定的同步荧光分析方法。在pH 7.8 KH2PO4-NaOH缓冲溶液中,于Δλ为70 nm的条件下对黄蝶呤及其它蝶呤类化合物进行同步荧光扫描,所得的重叠波谱数据用主成分回归法(PCR)、偏最小二乘法(PLS)、经典最小二乘法(CLS)和径向基人工神经网络(RBF-ANN)等多元校正法进行处理,结果表明偏最小二乘法(PLS)的分析结果最好,其标准偏差为4.29%。该方法简便、快速、准确,避免了较繁琐的样品前处理过程,应用于人尿中黄蝶呤分析,结果令人满意。     

高效液相色谱-荧光分析法同时测定人体尿液中黄蝶呤与异黄蝶呤

建立了高效液相色谱-荧光法同时测定癌症病人尿液中黄蝶呤及异黄蝶呤的新方法。选择荧光检测波长λex=345nm,λem=420nm。以磷酸盐缓冲溶液(pH=7.5)-甲醇(体积比为98∶2)为流动相,流速1.0mL/min,黄蝶呤与异黄蝶呤含量分别在0.0013～0.945μg/mL及0.00017～0.118μg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数分别为0.9999和0.9996,检出限分别为0.5ng/mL和0.05ng/mL,加标平均回收率在86.2%～107.5%之间。方法应用于癌症病人尿样分析,取得了较好的结果。     

UPLC-DAD测定大鼠尿液中的黄蝶呤、异黄蝶呤、酪氨酸和色氨酸

建立了大鼠尿液中黄蝶呤、异黄蝶呤、酪氨酸和色氨酸的超高效液相色谱-二极管阵列检测器检测(UPLC-DAD)分析方法,选择肌酐作为内标物来减少个体差异的影响。大鼠尿液利用甲醇除蛋白后,采取C18固相萃取小柱进行净化,然后用UPLC-DAD法进行测定,5种物质的仪器检出限分别为0.011,0.007,0.030,0.025和0.003 mg/L,加标回收率除黄蝶呤在60.8%～80.7%之间,其余各物质回收率均在96.3%～106.3%之间,RSD小于9.9%。     

高效液相色谱-电喷雾质谱同时测定人体尿液中黄蝶呤与异黄蝶呤

建立了高效液相色谱-电喷雾质谱(HPLC-ESI-MS)法同时测定人体尿液中黄蝶呤与异黄蝶呤的分析方法.尿样经离心、过膜后直接进样,采用电喷雾质谱进行定性和定量.结果表明,黄蝶呤与异黄蝶呤含量分别在0.0204～2.04μg/mL和0.0202～ 2.02 μg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数r2...     

纸色谱分离-荧光检测法测定人体尿液中的黄蝶呤

报道用丙醇-氨水(25％)-水(15：9：6．V／V)作展开剂,纸色谱分离人体尿液中的蝶呤类化合物,并利用黄蝶呤与其它蝶呤类化合物的荧光性质的差异来测定人体尿液中黄蝶呤的含量。黄蝶呤在0～0．6μg／10mL的范围内,其荧光强度与其荧光斑点的洗脱量呈良好的线性关系,从而建立了一种新的测定黄蝶呤的方法。该方法应用于人体尿液中黄蝶呤的测定,结果满意。     

薄层色谱-荧光检测法测定尿样中的黄蝶呤

系统研究了在展开剂V(正丙醇)∶V(浓氨水)=2∶3中利用薄层层析将尿液中的黄蝶呤和其它蝶呤类化合物分离,然后利用薄层荧光扫描法测定黄蝶呤。黄蝶呤在0.01～0.08μg范围内,其荧光斑点的积分面积与黄蝶呤的检测量呈良好的线性关系,从而建立了黄蝶呤的新的检测方法。方法可应用于尿样中的黄蝶呤测定。     

分光光度法测定生物试样中的黄蝶呤

在pH1．7条件下,黄蝶呤可将Fe^3＋还原为Fe^2＋,Fe^2＋与1,10-邻二氮菲形成有色络合物（λmax=510nm）,借此可用光度法测定黄蝶呤。黄蝶呤的含量在0～30μg／25mL范围内符合比耳定律。本法已应用于合成样中黄蝶呤的测定,结果满意。     

高效液相色谱法测定生物样品中多种蝶呤类化合物

建立了一种同时分离测定人体尿液中4种蝶呤类化合物(新蝶呤、异黄蝶呤、蝶呤和生物蝶呤)的高效液相色谱法。采用SHIMADZU Shim-pack:Vp-ODS(250 mm×4.6 mm×5μm)色谱柱结合荧光检测器,在流动相为甲醇-水(10+90),流速1.0mL/min,荧光检测波长Ex390 nm,Em450 nm,柱温为室温的色谱条件下,4种蝶呤类化合物分离效果良好。尿液经0.45μm的一次性滤膜过滤,取10μL滤液直接进样测定。结果表明,各组分的线性范围为:新蝶呤0.05～1.20μg/mL,异黄蝶呤0.05～0.80μg/mL,蝶呤0.05～1.00μg/mL,生物蝶呤0.05～1.00μg/mL。4种组分的检测限均为0.01μg/mL。该方法可应用于临床癌症病人和健康人尿样中4种蝶呤类化合物的检测。     

固相萃取-高效阴离子交换色谱-积分脉冲安培法检测人体尿液中的异黄蝶呤

建立了固相萃取-高效阴离子交换色谱-积分脉冲安培法(SPE-HPAEC-IPAD)测定人体尿液中异黄蝶呤的分析方法。尿液经ENVI-18与732型阳离子交换柱串联萃取后,除去了大量干扰物质。采用IonPac AS21分析柱(250 mm×2 mm),以0.025 mol/L NaOH溶液为淋洗液,流速为0.40 mL/min,在优化的安培检测波形条件下,异黄蝶呤的质量浓度在0.005～0.200 mg/L范围内与峰面积呈良好的线性关系,相关系数为0.998 4,检出限为0.003 mg/L。健康人及癌症病人尿液在2 mg/L和5 mg/L两个添加水平的平均回收率在95.4%～96.8%之间,相对标准偏差小于5%。此方法环保、快速、准确,可用于健康人与癌症病人尿液中异黄蝶呤的测定。     

Recent developments in multi-component synchronous fluorescence scan analysis

The ability to analyse complex multi-component mixtures without resorting to tedious separation procedures is extremely useful for routine analysis. Single-wavelength fluorescence measurement is limited in its ability to analyse complicated multi-component samples when they have severely overlapping emission and/or excitation spectra. This can be overcome by using synchronous fluorescence scan (SFS), where overlapping of spectra can be minimized. The selectivity of SFS can still be increased by taking derivative spectrum, applying different multivariate methods, selective fluorescence quenching, three-dimensional synchronous measurement or using some of these procedures in combination. Recent developments in various synchronous fluorescence methods for analysis of multi-component systems are discussed in this review.     

Application of synchronous fluorescence scan spectroscopy for size dependent simultaneous analysis of CdTe nanocrystals and their mixtures

In this paper, synchronous fluorescence scan (SFS) spectroscopy has been applied for the first time for the simultaneous determination of a mixture of CdTe fluorescent nanocrystals (NCs) of various sizes without a pre-separation step. It is observed that synchronous fluorescence maximum correlates well with the size of the nanocrystals, i.e.; the is useful to determine size dependency of NCs. Synchronous fluorescence maximum along with the second derivative can identify individual NCs in a mixture in water. The method is found to be simple, sensitive, selective and fast for NCs determination in aqueous media.     

CdTe量子点同步荧光法测定人血清白蛋白

以巯基乙酸(HS-CH2COOH)为稳定剂,水相中合成了CdTe量子点.在pH 6.40的0.002 mol/L KH2PO4-Na2HPO4缓冲溶液中,固定波长差为220 nm时一定量蛋白质的加入能明显增强量子点的同步荧光强度,并且荧光峰强度增加值与血清白蛋白浓度间存在良好的线性关系,据此建立了一种高灵敏度的测定微量蛋白质的方法.该方法测定人血清白蛋白的线性范围为0.08～2.80 μg/mL,检出限为0.032 μg/mL,10次重复测定1.80 μg/mL的血清白蛋白相对标准偏差为1.1%,已用于实际样品的测定.     

同步荧光法测定西双版纳热带雨林沉积物中的叶绿素及其环境意义

沉积物中的叶绿素及其衍生物不易变化,是生产力的敏感指标。因此,根据其含量和种类可探查陆地生态系统的初级生产力。讨论了沉积物中叶绿素的提取及同步荧光测定叶绿素的方法,并应用于西双版纳热带雨林沉积物中叶绿素的测定,并对其环境意义进行了初步研究。研究发现,在最佳实验条件下,叶绿素a、b的浓度在0.5～200μg/L范围内与荧光信号呈良好的线性关系,相关系数分别为0.9994、0.9999;其检出限分别为1.410和0.376μg/L。本方法适合批量测定,为沉积物中低含量叶绿素的测定提供了一种简单而快速的测定方法。     

氰基乙基-5-氯尿嘧啶核苷探针测定蛋白质的同步荧光法研究

基于核苷类药物中间体氰基乙基-5-氯尿嘧啶(CECU)与血清白蛋白相互作用生成复合物,导致血清白蛋白的内源荧光产生特异性变化,而建立了以氰基乙基-5-氯尿嘧啶为荧光探针,用固定波长同步荧光光谱技术测定人血清白蛋白(HSA)和牛血清白蛋白(BSA)的新方法。结果表明,在最佳实验条件下,体系的荧光强度与人血清白蛋白和牛血清白蛋白分别在2.76~497μg/mL和3.90~507μg/mL范围内呈良好的线性关系,检出限分别为1.64和1.72μg/mL(n=11)。该方法灵敏度高、稳定时间长、选择性好、线性范围宽。方法已用于血清样品中蛋白质的快速测定。     

Determination of uranium in human urine by total reflection X-ray fluorescence

Uranium has been classified as a toxic chemical. It affects the kidneys, with nephritis being the primarily chemically-induced effect in animals and humans. Intermediate-term studies on animals indicate that increased uranium doses are positively correlated with various biochemical effects and histopathological changes. Since the kidneys efficiently excrete in urine the major portion of solubilized uranium circulating in blood, an increased urinary uranium excretion can provide a sensitive quantitative measure of exposure, especially in the case of acute exposure. In the present work a method was developed for the quantitative determination of uranium in human urine. It combines the chemical treatment of urine, which results in a significant pre-concentration of uranium, with its subsequent detection by means of total reflection X-ray fluorescence (TXRF). The method has been proven to be relatively fast, offering detection limits that allow for monitoring uranium intake above normal levels.     

二阶导数-同步荧光法同时测定微量维生素B_1,B_2和烟酰胺

建立了二阶导数-同步荧光法同时测定微量维生素B1,B2和烟酰胺含量的方法.在最佳实验条件下,维生素B1,B2和烟酰胺的检测限分别为2.1,2.6,和2.8 ng/mL,相对标准偏差为1.5%～4.9%,加标回收率为92%～105%.该方法可用于样品中微量维生素的测定.     

Determination of phenol, resorcinol and hydroquinone in air samples by synchronous fluorescence using partial least-squares (PLS)

The determination of phenolic compounds is of great importance owing to their high toxicity. Some of them are present in tobacco smoke and it is important for their monitoring in air of closed room. A simple, rapid and sensitive method was developed for simultaneous determination of hydroquinone, resorcinol and phenol in this kind of samples. Synchronous fluorescence technique was used and the data were processed by using the partial least-squares (PLS) chemometric algorithm. The concentrations for experimental calibration matrix were varied between 0.02 and 0.2 mg L⁻¹ for hydroquinone, between 0.05 and 0.6 mg L⁻¹ for resorcinol and between 0.05 and 0.4 mg L⁻¹ for phenol in accordance with the national legislation. The cross-validation method was used to select the number of factors. To check the accuracy of the proposed method a recovery study on real samples was carried out.     

Protein determination using methylene blue in a synchronous fluorescence technique

A new method for detecting protein by synchronous fluorescence enhancement was developed, based on the combination of near infrared (NIR) fluorescence and the dedimerization phenomenon of methylene blue (MB). Under analytical conditions, there are linear relationships between the enhancing extent of synchronous fluorescence of MB-sodium dodecyl benzene sulfonate (SDBS)-protein at 667 nm and the concentration of protein in the range of 8.0 × 10⁻⁸-4.0 × 10⁻⁵ g mL⁻¹ for bovine serum albumin (BSA), 1.0 × 10⁻⁷-3.5 × 10⁻⁵ g mL⁻¹ for egg albumin (EA). The detection limits (S/N = 3) of BSA and EA are 8.9 ng mL⁻¹ and 10.0 ng mL⁻¹, respectively. The fluorescence enhancement mechanism is discussed in detail. Results from multiple techniques indicate that the fluorescence enhancement of the system originates from the hydrophobic microenvironment provided by BSA and SDBS, and the formation of an MB-SDBS-BSA complex, as well as the deaggregation of some MB dimer.