A sensitive resveratrol assay with a simple probe methylene blue by resonance light scattering technique

A novel resonance light scattering (RLS) method was developed for the determination of resveratrol based on the interaction between resveratrol and methylene blue (MB). It was found that at pH 8.69, the weak RLS intensity of MB was remarkably enhanced by the addition of trace amount of resveratrol with the maximum peak located at 385.0 nm. Under the optimum conditions, a good linear relationship between the enhanced RLS intensities and the concentrations of resveratrol was obtained over the range of 2.0-14.0 μg ml(-1) with the detection limit (3σ) of 0.63 μg ml(-1). The results of the analysis of resveratrol in synthetic samples and human urine are satisfactory, which showed it may provide a more sensitive, convenient, rapid and reproducible method for the detection of resveratrol, especially in biological and pharmaceutical field. In this work, the characteristics of RLS, absorption and fluorescence spectra of the resveratrol-MB system, the influencing factors and the optimum conditions of the reaction were investigated.     

A Novel Protein Assay With an Azo Dye Using Rayleigh Light Scattering Technioque

ABSTRACT

The interaction of SPADNS [3-(4-sulfophenylazo)-4, 5-dihydroxy-2, 7-naphthalene disulfonic acid] with proteins in acidic solution was studied by spectrophotometric and Rayleigh light scattering (RLS) methods. SPADNS reacts rapidly with albumin at room temperature, and the intensity of the weak RLS of SPADNS was enhanced remarkably and quantitatively by this reaction.

Based on this observation, a novel RLS method for serum albumin determination was developed. The linear range is 0.125-14.9 μg/ml for BSA. The relative standard deviation (n=10) for 5.0 μg/ml BSA was 3.94%. The method was applied to the determination of proteins in human plasma, and the results were compared with the traditional proteins assay (CBB method). There is almost no interference from amino acids, metal ions and other coexistent substances. The reaction mechanism was also discussed.     

灿烂甲酚蓝共振光谱散射法测定脱氧核糖核酸

研究了灿烂甲酚蓝与脱氧核糖核酸（DNA）作用的共振光散射光谱,在pH＝10．8－11．5的范围内,DNA的加入导致灿烂甲酚蓝共振光散射的增强,在347nm处,存在一共振光散射增强峰,其强度与DNA的浓度呈线性关系,据此建立了一种测定DNA的共振光谱散射法。该方法的线范围为80－100μg/L,检出限为23．3μg/L.     

Study on naringenin-CTMAB-DNA system by resonance light scattering technique and its analytical application

A new high-sensitivity determination method of deoxyribonucleic acid (DNA) with detection limit at nanogram levels was proposed. Based on the measurement of resonance light scattering (RLS), it was found DNA could combine with naringenin and cetyltrimethylammonium bromide (CTMAB) in basic Tris-HCl buffer and produce enhanced RLS signal. The optimum conditions for this system were studied in detail. The enhanced intensity of RLS of naringenin-CTMAB at 353 nm was directly proportional to the concentration of DNA in the range of 0.017-1.7 μg mL(-1). The detection limit was 5.06 ng mL(-1). Using the proposed method, the synthetic samples were analyzed with satisfactory results, the recovery was 99.3-105.0% and RSD was 0.7-3.7%.     

Resonance scattering amplification assay of biomolecules based on the biomineralization of gold nanoparticles bioconjugates

A novel method was designed for the determination of trace protein with high sensitivity. This sensing method combined the principle of biomineralization and the resonance scattering (RLS) assay of gold nanoparticles (AuNPs). AuNPs were synthesized in the presence of polpyropylneimine hexadeacamnie dendrimers (PPIHA). Meanwhile, they were superficially modified with the amine group, which was confirmed by Fourier transform infrared spectra (FTIR). The specific covalent coupling between bovine serum albumin (BSA) and amine-AuNPs assembles a hyperefficient crystal core. Based on the principle of biomineralization, Au(3+) ions were reduced to Au at the surface of bioconjugates in the HAuCl(4)-NH(4)OH·HCl redox system. Thus, the size of AuNPs-BSA was selectively enhanced. Meanwhile, the concentration signal of BSA was converted to the RLS intensity of AuNPs, which was enhanced through this process. The selective amplification of RLS signal laid the foundation of the detection method, as it intensified with the increase of AuNPs-BSA concentration. Experimental results show that the peak intensity at 548 nm is proportional to the concentration gradient of the bioconjugates from 0.268 μg/ml to 1.608 μg/ml under the optimized conditions. Additionally, the method has high sensitivity with detection limit as low as 0.096 μg/ml. The specific coupling with high sensitivity and good stability of this method indicates its possibility for the assay of other proteins. Moreover, the novel method achieves quantitative detection of trace proteins, suggesting the potential of AuNPs-based analytical methods in further application.     

花菁-脱氧核糖核酸的共振光散射光谱及其分析应用

研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强。在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法。方法的线性范围为:小牛胸腺DNA(CT DNA),0～20μg/mL,鱼精子DNA(FS DNA),0～15μg/mL;检出限分别为0.005μg/mL和0.008μg/mL。该方法已用于合成样品中DNA的测定。     

四羧基铜酞菁共振散射法测定硫酸庆大霉素

在弱酸性条件下,四羧基铜酞菁(CuC4Pc)与硫酸庆大霉素(GEN)反应形成离子缔合物,使体系的共振散射强度增大,据此建立了以四羧基铜酞菁为探针测定GEN的新方法.在λ为362 nm处,共振散射强度(△IRLS)最大且△IRLS与GEN的浓度在0.05～1.50μg/mL范围内成正比,检出限为0.044μg/mL.将方法用于硫酸庆大霉素注射液的测定,结果满意。     

Development and validation of a new RP-HPLC method for determination of quercetin in green tea

Green tea (Camellia sinensis) contains quercetin as a bioactive compound. Quercetin has anti-inflammatory and anticancer effects. The aim of this paper was to develop and validate an RP-HPLC method for determination of quercetin in green tea simpler and faster than other available methods. RP-HPLC analysis was performed by isocratic elution with a flow rate of 1.0 mL/min. Pure methanol was used as a mobile phase, while the quantification was effected at 370 nm. The separation was performed at 35°C using a C₁₈ column (4.6 × 250 mm, 5 μm). The results showed that the peak area response is linear within the concentration range of 10–70 μg/mL (r = 0.9986). The values of LOD and LOQ were 1.2 and 4 μg/mL, respectively. For the intra-day and intra-instrument reproducibility, RSD were in the range of 0.05–0.84% and 0.89–1.55%, respectively. The results of accuracy for the different concentrations of quercetin (40, 50 and 60 μg/mL) were 101.3, 98.4, and 98.2%. The developed and validated method was successfully applied to the determination of quercetin in green tea extract.     

同多酸和染料探针共振光散射法测定蛋白质

在酸性条件下,铬黑T、钼酸铵与蛋白质形成聚合物,使体系的共振光散射明显增强。据此建立了利用共振光散射技术测定总蛋白含量的新方法。在最佳条件下,体系的最大散射峰位于555nm处。共振光散射增强的程度与蛋白质的浓度呈良好的线性关系。牛血清白蛋白和人血清白蛋白的线性范围分别为0.20～10.0μg/mL和0.10～8.0μg/mL,检出限为0.050μg/mL和0.039μg/mL。方法已用于人血清样品的分析,并与考马斯亮蓝的测定结果进行了比较,两者无显著性差异。     

瑞利光散射技术快速测定萝卜红色素中痕量Pb(Ⅱ)

建立了快速测定Pb(Ⅱ)的瑞利散射(RLS)新方法。在Tris-HCl缓冲介质中,溴化十六烷基三甲基铵(CTMAB)增敏溴甲酚绿(BCG),使瑞利散射显著增强,最大瑞利散射峰位于345nm,CTMAB-BCG进一步与Pb(Ⅱ)结合后生成的三元复合物的瑞利散射增强程度(|ΔIRLS|)与0.006~0.41mg/L范围Pb(Ⅱ)的质量浓度呈线性关系,定量限为0.053mg/kg。方法用于萝卜红色素中Pb(Ⅱ)的测定,回收率为98.5%~102%,相对标准偏差为1.8%~2.5%。     

共振光散射光谱法测定氯代十六烷基吡啶的研究

阳离子表面活性剂(Cationic Surfactants,CS)具有杀菌消毒和很强的吸附特性,被广泛应用于日用化工、工业洗涤剂、制药等行业,在人类生产生活中的应用日益广泛。但进入水体的阳离子表面活性剂会消耗水中的溶解氧,危害水体的生态环境而且抑制其它有毒物质的降解,导致严重的水质污     

孔雀石绿共振光散射法测定饮用水中痕量BrO3-

在pH3.8的HAc-NaAc缓冲液中,BrO3-氧化I-生成I2,I2与过量的I-反应生成I3-,I3-与孔雀石绿(MG)反应形成缔合微粒,导致体系的共振光散射强度急剧增强,最大共振光散射波长位于465nm处,BrO3-浓度在0～120μg/L范围内有较好线性关系,检出限以3σ计算为3.4ng/mL,据此建立了一种测定微量BrO3-的共振光谱新方法.该法用于饮用水中BrO3-的测定,得到了满意的结果.     

Nucleic acids analysis with nano-Ag-Tb(III) by a resonance light scattering technique.

The nano-Ag-terbium(III)-mucleic acids system was observed by a resonance light scattering (RLS) technique for the first time, and the quantitative analysis of nucleic acids at nanogram levels was established. Studies showed that the RLS intensity of the nano-Ag-terbium(III) system can be obviously enhanced by nucleic acid, which was characterized by the RLS spectrum and the UV-Vis spectrum. In this system, the nanoparticles were only of a definite size and in a limited particle concentration region. Further research indicated that under the optimum conditions, the enhanced intensity of RLS is in proportion to the concentration of nucleic acids in the ranges of 7.0 x 10(-9) g ml(-1) to 8.0 x 10(-6) g ml(-1) for calf thymus DNA (ctDNA), 2.0 x 10(-8) g ml(-1) to 1.0 x 10(-6) g ml(-1) for fish sperm DNA (fsDNA) and 1.0 x 10(-9) g ml(-1) to 1.0 x 10(-7) g ml(-1) for yeast RNA (yRNA). The detection limits were 1.4 ng ml(-1) for ctDNA, 1.2 ng ml(-1) for fsDNA and 0.85 ng ml(-1) for yRNA, respectively. Synthetic and real samples were determined satisfactorily.     

Determination of nucleic acids at nanogram level using resonance light scattering technique with Congo Red

Based on the enhancement of the resonance light scattering (RLS) of Congo Red (CR) by nucleic acid, a new quantitative method for nucleic acid is developed. In the Tris-HCl buffer (pH 10.5), the weak light scattering of CR is greatly enhanced by addition of nucleic acid and CTMAB, the maximum peak is at 560 nm and the enhanced intensity of RLS is in proportion to the concentration of nucleic acid. The linear range is 1.0 x 10(-9) to 1.0 x 10(-6) g ml(-1), 7.5 x 10(-8) to 1.0 x 10(-6) g ml(-1) and 7.5 x 10(-8) to 2.5 x 10(-6) g ml(-1) for herring sperm DNA, calf thymus DNA and yeast RNA, and the detection limits are 0.019, 0.89 and 1.2 ng ml(-1) (S/N = 3), respectively. Actual biological samples were satisfactorily determined.     

荧光素染料与富马酸酮替芬的光谱研究及应用

在弱酸性缓冲介质中,富马酸酮替芬和某些卤代荧光素类染料(曙红Y、荧光桃红和曙红B)借助静电引力和疏水作用力形成离子缔合物,引起共振光散射光谱、吸收光谱及荧光光谱的变化。实验表明,曙红Y体系灵敏度最高。对曙红Y、荧光桃红和曙红B体系,线性范围分别为0.12~8.4μg/mL、0.24~8.4μg/mL和0.18~6.0μg/mL,检测限分别为12.72 ng/mL、12.52μg/mL和18.21μg/mL。方法已用于分析富马酸酮替芬片剂、血清及尿样。     

基于与Ce3+相互作用共振光散射法测定三磷酸腺苷二钠

在Tris-HCl缓冲溶液中, 三磷酸腺苷二钠(ATP)与铈离子(Ce³⁺)相互作用产生很强的共振光散射(RLS)信号。实验表明,增强的散射信号与ATP的浓度在2.0~24 μmol/L范围内呈线性关系,据此建立了一种测定三磷酸腺苷的共振光散射法,检测限(S/N=3σ)为51.25 nmol/L。研究了共存物质的影响,用于临床三磷酸腺苷注射液的测定, RSD=2.29%。     

分散固相萃取-气相色谱-质谱法测定含油脂食品中17种邻苯二甲酸酯

建立了含油脂食品中17种邻苯二甲酸酯的分散固相萃取-气相色谱-质谱法检测方法。奶茶样品经乙腈-甲基叔丁基醚(9∶1,V/V)提取后,提取液用MAS-PAEC分散固相萃取管进行净化。调味包样品经乙腈(正己烷饱和)-甲基叔丁基醚(19∶1,V/V)提取2次后,提取液用CNW分散固相萃取管进行净化。采用基质匹配标准外标法进行定量分析。结果表明,奶茶中17种邻苯二甲酸酯的加标回收率为82.2%～125.4%;相对标准偏差小于16.5%;方法检出限为100～200μg/L。调味包中17种邻苯二甲酸酯的加标回收率为70.9%～115.5%;相对标准偏差小于9.8%;方法检出限为400～800μg/L。本方法快速、精确、简易、廉价、稳定,可应用于含油脂食品中17种邻苯二甲酸酯的实际检测分析。     

硫代乙酰胺共振光散射方法检测环境水样中痕量汞

在pH=3.29的酸性介质中,硫代乙酰胺(TAA)与二价汞离子发生作用产生以379.0 nm为特征峰的共振光散射(RLS)增强光谱。 在此波长下,二价汞离子的浓度与增强共振光散射强度(ΔIRLS)呈线性关系。 研究了酸度、离子强度、温度、时间以及共存物质的影响,确定了最佳测定条件,据此建立了检测痕量汞的共振光散射分析法,线性范围为0.2~10.0 μmol/L,对汞的检测限为0.02 μmol/L。 方法成功的应用于环境水样中汞离子的检测。     

硅钨酸与盐酸巴马汀相互作用光谱研究及其分析应用

在pH 为0.91 的HCl-NaOAc 缓冲介质中, 盐酸巴马汀与硅钨酸通过静电相互作用导致共振光散射信号显著增强,最大散射波长为297 nm, 增强的散射信号强度与盐酸巴马汀浓度在0.09～3.2 μg/mL 范围内呈线性关系, 据此建立了盐酸巴马汀的共振光散射分析方法, 检测限为9.1 ng/mL. 实验考察了pH、离子强度对体系的影响, 研究了体系紫外吸收光谱及荧光光谱, 讨论了共振光散射增强机理. 该方法用于黄藤素片、黄藤素胶囊及血清样品中盐酸巴马汀含量测定,RSD≤4.2%.     

液相色谱串联质谱法测定养殖水体中孔雀石绿及其代谢物

研究利用液相色谱-串联质谱(LC-ESI-MS/MS)测定水产品养殖水体中孔雀石绿及其代谢物隐性孔雀石绿的方法.通过一系列实验对样品前处理条件进行了优化研究,养殖水样经乙酸酸化,净化后,采用HPLC-ESI-MS/MS检测分析.在多反应监测模式(MRM)下,外标法定量,定量限均为0.5μg/kg.在0.5～50μg/L...