用共振光散射技术研究蛋白质与丽春红2R的相互作用

在pH3．50的Britton-Robinson缓冲溶液中，丽春红2R与蛋白质发生结合反应，使最大波长为352．5nm的共振散射光谱得到加强。据此建立了利用丽春红2R作探针，用共振散射光谱技术测定蛋白质的新方法。散射光强度与牛血清白蛋白(BSA)、人血清白蛋白(HAS)和免疫球蛋白(IgG)的浓度在0．25～17．5μg／mL范围内成正比。方法的稳定性好，快速、简便，绝大多数氨基酸、金属离子均不产生干扰，用于人血清样品中蛋白质的测定，获得了满意的结果，加标回收率为93．4％～100．1％。     

共振光散射光谱研究噻嗪红R与牛血清白蛋白的作用及其分析应用

研究了噻嗪红R(Thiazine red R,TR)与牛血清蛋白(BSA)作用的共振光散射(RLS)光谱特征。考察了各种影响因素,并计算出了BSA与TR的结合比(质量之比)为1.25。结果表明,在优化条件下体系的RLS强度与蛋白质浓度在一定范围内具有良好的线性关系,据此建立了一种蛋白质测定的新方法。在最佳实验条件(TR,2.0×10-5mol/L;pH2.36)下,BSA的线性范围是0.01~5.0μg/mL,检出限为1.4ng/mL。该方法已用于合成样品及尿液的测定。     

茜素绿-蛋白质体系的共振瑞利散射光谱及其分析应用

基于蛋白质对茜素绿共振瑞利散射的增强作用,建立了一种测定水溶性蛋白质的新方法.在酸性BR缓冲溶液中,茜素绿在365 nm处的共振光散射增强与蛋白质浓度呈线性关系.对人血清白蛋白、牛血清白蛋白、γ-人球蛋白、卵白蛋白测定的检出限均低于14 ng/mL.该方法灵敏、稳定、选择性好,适用于人血清、尿液中总蛋白质的测定.     

Resonance scattering method for the ultrasensitive determination of peptides using semiconductor nanocrystals

Resonance light scattering (RLS) of the functionalized ZnS nanocrystals-peptides system and its analytical application have been studied. The RLS intensity can be efficiently enhanced when various peptides were added. The mechanism of the RLS enhancement of ZnS nanocrystals was discussed. The change of RLS intensity was in proportion to the concentration of peptides. The limits of detection were in range of 2.8-5.7 ng mL⁻¹. Application results to synthetic samples showed simplicity, rapidity, high sensitivity and satisfactory reproducibility of the presented method. Measurements of real samples also give satisfactory results which were in good agreement with those obtained using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrography (LC-MS) methods.     

几种金属离子对胭脂红与牛血清白蛋白相互作用的影响——荧光光谱研究

利用荧光光谱法研究了不同温度(15、27、39℃)下食用合成色素胭脂红对牛血清白蛋白(BSA)的内源荧光猝灭特性,考察了Cu2+、Ni 2+、Pb2+等金属离子对二者相互作用的影响,并测定了不同温度下的猝灭常数KSV、结合常数KA和结合位点数n.结果表明,3种金属离子基本不影响胭脂红对BSA荧光猝灭机理,但Cu2+、Ni 2+、Pb2+离子都与BSA有一定的结合能力,可在不同程度上增强胭脂红与BSA的结合作用及其对BSA内源荧光的猝灭.     

藉L-半胱氨酸包覆的ZnS纳米粒子的共振光散射定量分析蛋白质

合成和表征了功能性L-半胱氨酸包覆的ZnS纳米粒子。在pH5．12的NaAc-HAc溶液介质中,L-半胱氨酸包覆ZnS纳米粒子于波长308．0nm处出现共振光散射峰。一定量蛋白质的加入能明显增强体系的共振光散射,且峰强度增加值与蛋白质浓度间存在良好线性关系,据此建立了一种灵敏的测定微量蛋白质的方法。用L-半胱氨酸包覆ZnS纳米粒子作为探针,不仅克服了有机染料可能出现的光漂白等缺点,而且本身不具毒性。该法用于人血清试样中总蛋白的测定,其结果与临床数据一致。     

Kinetic Spectrophotometric Determination of Ascorbic Acid in Pharmaceutical Samples by Oxidation of Ponceau 4R by Hydrogen Peroxide

A new sensitive and simple kinetic method is developed for determination of traces of ascorbic acid based on its activated effect on oxidation of trisodium‐2‐hydroxy‐1‐(4‐sulphonato‐1‐naphthylazo)naphthalene‐6,8‐disulphonato (red artificial color Ponceau 4R) by hydrogen peroxide, in the presence of Cu(II) as catalyst, in borate buffer. The reaction is followed spectrophotometrically by tracing the oxidation product at 478.4 nm within 1 min after addition of H₂O₂. The optimum reaction conditions are: borate buffer (pH = 11.00), Ponceau 4R (9.6·10^?6 mol/L), H₂O₂ (2·10^?2 mol/L), Cu(II) (8·10^?7 mol/L) at 22 °C. Following this procedure, ascorbic acid can be determined with a linear calibration graph up to 1.76 ng/mL and a detection limit of 0.28, based on 3S criterion. The relative error ranges between 6.77‐1.66% for the concentration interval of ascorbic acid 1.76‐17.61 ng/mL. The effects of certain foreign ions upon the reaction rate were determined for an assessment of the selectivity of the method. The method was applied for determination of ascorbic acid in pharmaceutical samples, and spectrophotometric method was used like an comparative method.     

Determination of trace proteins with pyronine Y and SDS by resonance light scattering

A new resonance light scattering (RLS) probe for determining proteins is presented. The weak RLS of pyronine Y–SDS can be enhanced substantially by adding proteins in the presence of H₂SO₄, resulting in a strong and wide RLS band in the region 310–425 nm. The interaction of pyronine Y–SDS with proteins was studied on the basis of this behavior and a new quantitative method was developed for determining proteins. The enhanced RLS intensity is proportional to the concentration of proteins in the range 0.15–3.6 μg mL⁻¹ for bovine serum albumin (BSA) and 0.06–4.8 μg mL⁻¹ for human serum albumin (HSA), with detection limits of 21.0 and 12.0 ng mL⁻¹, respectively. This method is characterized by high sensitivity, rapidity of reaction, and simplicity. Four synthetic samples were determined satisfactorily and recovery was 99.5–101.5%. Results for human serum and urine samples were in agreement with those obtained by the Bradford method, with relative standard deviations (RSD) of 1.5–3.1%.     

A new and sensitive resonance-scattering method for determination of trace nitrite in water with rhodamine 6G

In the medium HCl–KI–rhodamine dye, NO₂^– reacts with excess I^– to form I₃^– and the I₃^– and rhodamine dye combine to form an association particle which gives three resonance-scattering (RS) peaks at 320 nm, 400 nm, and 595 nm. In systems containing rhodamine 6G (Rh6G), rhodamine B (RhB), rhodamine S (RhS), and butyl rhodamine B (BRhB) the resonance scattering intensity at 400 nm is proportional to nitrite concentrations in the range 2.3–276 ng mL^–1, 9.2–184 ng mL^–1, 9.2–184 ng mL^–1, and 9.2–92 ng mL^–1, respectively. Because of the high sensitivity, wide linear range, and good stability of the Rh6G system, it has been used for determination of nitrite in water samples, with satisfactory results. The spectral results have been used to verify that the formation of (Rh6G·I₃)_n association particles and their interface with the system are main factors that cause the RS enhancement.     

Study of the interaction of Azur B with DNA and the determination of DNA based on resonance light scattering measurements

Based on the measurements of molecular absorption and resonance light scattering (RLS), the aggregation of Azur B (AB) was in a medium of pH ranging from 1.98 to 2.56 and ionic strength <0.12 M. The presence of double stranded DNA prompts the aggregation, resulting in enhanced RLS signals. Linear relationships were achieved between the enhanced RLS intensity at 359.7 nm and DNA concentration in the range of 0-4.5 μg ml⁻¹ for both calf thymus DNA (ctDNA) and fish sperm DNA (fsDNA) if 3.0×10⁻⁵ M AB was employed. The 3σ limits of detection were 9.3 and 8.9 ng ml⁻¹ for ctDNA and fsDNA, respectively. Five synthetic samples were analysed satisfactorily.     

木质素桃红与蛋白质作用的共振光散射研究

研究了木质素桃红与蛋白质结合的共振光散射光谱. 实验结果表明, 在pH 2.56的酸性介质中, 木质素桃红与蛋白质发生静电作用产生以282.0、 346.0、 420.0 nm以及570.0 nm为特征峰的共振光散射（RLS）增强光谱. 在570.0 nm波长光激发下, 蛋白质的质量浓度与增强共振光散射强度ΔIRLS呈线性关系, 对BSA和HSA的检出限分别为39.0和22.3 ng/mL. 方法已用于尿样中总蛋白质分析.     

Simultaneous Determination of Anthocyanin and Ponceau 4R in Drink Powders by Derivative Spectrophotometry and Partial Least-Squares Multivariate Spectrophotometric Calibration

Summary.  Two methods for the simultaneous determination of anthocyanin and ponceau 4R in drink powders by second derivative spectrophotometry and by partial least-squares multivariate spectrophotometric calibration are described. The procedures do not require any separation step. The methods were applied to determine both colorants in commercial gelatin powders; the results obtained are compared. Received September 7, 2000. Accepted (revised) November 20, 2000     

基于与全氟辛烷磺酸作用共振光散射法测定盐酸小檗碱

在pH 1.81 Britton-Robinson缓冲介质中,盐酸小檗碱与全氟辛烷磺酸相互作用,在290 nm处产生显著增强的散射信号.其增强强度与盐酸小檗碱质量浓度在0.03～7.8μg/mL范围内呈线性关系,据此建立了盐酸小檗碱的共振光散射测定方法,检出限达4.4 ng/mL.方法用于药片含量测定,RSD<4.4%...     

A simple and sensitive assay of nucleic acids based on the enhanced resonance light scattering of zwitterionics

A new assay of nucleic acids at nanogram level was established based on the enhanced resonance light scattering (RLS) signals of two zwitterionics cocamidopropyl hydroxysultaine (HSB) and lauryl betaine (BS-12). Under optimum conditions, the weak RLS signal of HSB is enhanced by nucleic acids, and the enhanced RLS intensity is proportional to the concentration of nucleic acids in the range of 0.02–7.3 mg l⁻¹ for calf thymus DNA and 0.01–8.6 mg l⁻¹ for fish sperm DNA. The detection limits were 1.5 ng ml⁻¹ for calf thymus DNA and 1.9 ng ml⁻¹ for fish sperm DNA. Plasmid DNA extracted from K-12-HB101 colt was determined with satisfactory results.     

Study on the interaction between nucleic acid and Eu3+-oxolinic acid and the determination of nucleic acid using the resonance light scattering technique

At pH 9.75, the resonance light scattering (RLS) intensity of OA–Eu³⁺ system is greatly enhanced by nucleic acid. Based on this phenomenon, a new quantitative method for nucleic acid in aqueous solution has been developed. Under the optimum condition, the enhanced RLS is proportional to the concentration of nucleic acid in the range of 1.0 × 10⁻⁹ to 1.0 × 10⁻⁶ g/ml for herring sperm DNA, 8.0 × 10⁻¹⁰ to 1.0 × 10⁻⁶ g/ml for calf thymus DNA and 1.0 × 10⁻⁹ to 1.0 × 10⁻⁶ g/ml for yeast RNA, and their detection limits are 0.020, 0.011 and 0.010 ng/ml, respectively. Synthetic samples and actual samples were satisfactorily determined. In addition, the interaction mechanism between nucleic acid and OA–Eu³⁺ is also investigated.     

A sensitive resonance light scattering spectrometry of trace Hg with sulfur ion modified gold nanoparticles

A new resonance light scattering (RLS) spectrometric method for mercury ions (Hg²⁺) in aqueous solutions with sulfur ion (S²⁻) modified gold nanoparticles (Au-NPs-S) has been developed in this contribution. It was found that S²⁻ at the surface of Au-NPs resulting from the surface modification can interact with Hg²⁺ to form very stable S-Hg-S bonds when Hg²⁺ concentration is lower than that of S²⁻, resulting in the aggregation of Au-NPs-S and causing enhanced RLS signals. The enhanced RLS intensities (ΔI_RLS) characterized at 392 nm were found to be proportional to the concentration of Hg²⁺ in the range of 0.025-0.25 μmol L⁻¹ with a detection limit (3σ) of 0.013 μmol L⁻¹. Our results showed that this approach has excellent selectivity for Hg²⁺ over other substances in aqueous solutions.     

银的流动注射共振光散射法测定

利用自制的流通池,研究了流动注射分析与共振光散射光谱法联用的测定技术;探讨了Ag的流动注射和共振光散射光谱测定的工作条件;Ag的线性范围为0～100 μg/mL,检出限为0.136 μg/mL,测定频率为43次/h;实验结果表明本文所建立的方法快速、所需的化学试剂少.     

A highly sensitive and selective resonance Rayleigh scattering method for Hg2+ based on the nanocatalytic amplification

In 0.2 mol/L HCl–0.22 mol/L HNO₃ medium, trace Hg²⁺ catalyzed NaH₂PO₂ reduction of HAuCl₄ to form gold nanoparticles (AuNPs), which exhibited a strong resonance Rayleigh scattering (RRS) effect at 370 nm. With increasing of [Hg²⁺], the RRS effect enhanced due to more AuNP generated from the catalytic reaction. Under the chosen conditions, the enhanced RRS intensity at 370 nm is linear to Hg²⁺ concentration in the range of 5.0–450 × 10⁻⁹ mol/L, with a detection limit of 0.1 nmol/L. This RRS method was applied for the determination of Hg in water samples, with high sensitivity and good selectivity, and its results were agreement with that of atomic fluorescence spectrometry.     

高碘酸钾氧化丽春红-2R催化动力学单扫描示波极谱法测定痕量Fe(Ⅲ)的研究

研究了在H2SO4介质中,痕量Fe(Ⅲ)催化KIO4氧化丽春红-2R的褪色反应,提出了催化动力学单扫描示波极谱法测定痕量铁的新方法。在1.6×10-3mol/LH2SO4介质中,丽春红-2R在汞电极上产生1个灵敏的还原峰,峰电位为-0.224V(vs.SCE)左右;在KIO4存在下,丽春红-2R峰电流的降低与加入Fe(Ⅲ)质量浓度在0~0.04μg/mL范围内呈良好的线性关系,检出限达到6.28×10-9μg/mL。同时探讨了反应条件、极谱波的性质和电极反应机理,已用于中草药中铁的测定,回收率为98.9%~102.2%。     

Spectrophotometric Simultaneous Determination of Amaranth,Ponceau 4R,Allura Red and Red 2G by Partial Least Squares and Principal Component Regression Multivariate Calibration

ABSTRACT

The multivariate calibration methods, partial least square regression type 1 (PLS 1) and principal component regression (PCR), were proposed for the simultaneous spectrophotometry determination of Amaranth (E-123), Ponceau 4R (E-124), Allura red (E-129) and Red 2G (E-128) in their mixtures. The parameters of the chemometric procedures were optimized and the proposed method was validated with synthetic samples and applied to analyze these dyes in spiked samples of beverages with satisfactory results.