Resonance Rayleigh Scattering Intensity Research Articles

Resonance Rayleigh Scattering Spectra of Thorium (IV)‐bisazo Dye of Chromotropic Acid‐protein Systems and Their Analytical Applications

AbstractIn acidic medium, thorium (IV) can react with a bisazo dye of chromotropic adds such as arsenazo HI (AA in), arsenazo M (AA M), chlorophosphonazo III (CPA III) and chlorosulphonphenol S (CSP S) to form an anionic chelate which further interacts with some proteins to produce a complex. This results in a significant enhancement of intensity of the resonance Rayleigh scattering (RRS) and the appearance of a new RRS spectrum. There are a few obvious RRS peaks in the range of 400–470 nm and the most intensive peak of them is located at 470 nm. The intensity of RRS is directly proportional to the concentration of protein in the range of 0—l.öμg‐mL−1 for Th(IV)‐CPA III system, 0–2.8 μg‐mL−1 for Th(IV)‐AA M system, 0–2.0 μg·mL−1 for Th(IV)‐AA III system and 0–0.28 μg·mL−1 for Th(IV)‐CSP S system, respectively. The detection limits for BSA (3s̀) are 10.7 ng·mL−1 for Th (IV)‐CPA III, 6.3 ng·mL−1 for Th(IV)‐CSP S, 13.6 ng·mL−1 for Th(IV)‐AA III and 22.1 ng·mL−1 for Th(IV)‐AA M, respectively. This new RRS method has high sensitivity and fairly good selectivity and can be applied to the direct determination of proteins in human serum with satisfactory results.

Resonance Rayleigh Scattering Method for the Determination of Raloxifene with Evans Blue

AbstractThe intensity of resonance Rayleigh scattering (RRS) of Evans blue (EB) or raloxifene hydrochloride (Ralo) is very weak, but it can be enhanced significantly and a new RRS spectrum appears when both of them interact to form an ion‐association complex in sodium acetate‐hydrochloric acid buffer solution at pH 1.8. The intensity of RRS is directly proportional to the concentration of Ralo in the range of 0–8.3 μg · mL−1, and the detection limit for Ralo (σ = 3) is 18.9 ng·mL−1. The method has high sensitivity and fairly good selectivity. Based on the above evidences, a new facile method for the determination of trace amount of Ralo has been established with satisfactory results.

Resonance Rayleigh Scattering for the Determination of Berberine in Tablet Form with some Acidic Xanthene Fluorescent Dyes

A simple determination method of berberine with a limit of determination at the nanogram level is proposed under the use of a common spectrofluorometer to detect the intensity of resonance Rayleigh scattering (RRS). In aqueous solution at pH 4–5, berberine reacts with acidic xanthene fluorescent dyes such as eosine Y, erythrosine, ethyl eosin, phloxin and Rose Bengal to form an ion-associate. This results in a significant enhancement of RRS intensity and the appearance of new RRS spectra. The characteristics of RRS spectra of the ion-associates and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of berberine in the range of 0–5.0 × 10−6 mol/L. The procedures described have a very high sensitivity and the detection limits for berberine are 14–215 ng/ml, and the sensitivity order is eosine Y > erythrosine > ethyl eosin > > phloxin > rose Bengal. The results of analysis for synthetic samples were in good agreement with the desired values, and the ones for tablets were identical with those obtained with the procedure described in the Chinese Pharmacopoeia.

Resonance Rayleigh-scattering method for the determination of vitamin B1 with methyl orange.

In a pH 2.3-3.0 acid medium, the resonance Rayleigh scattering (RRS) intensity is greatly enhanced when vitamin B, reacts with Methyl Orange to form an ion-association complex. The maximum RRS peak appears at 588 nm, another higher peak is at 403 nm and there are two smaller RRS peaks at 800 nm and 288 nm. The RRS intensity is directly proportional to the concentration of vitamin B, in the range of 0-400 ng ml(-1). The method has high sensitivity and the detection limit (3sigma) for vitamin B1 is 7.2 ng ml(-1). The effects of coexisting substances on the determination of vitamin B, were investigated, and the results show that this method has good selectivity and can be applied to the direct determination of vitamin B1 in composite vitamin B tablets and multivitamin tablet samples.

A NEW METHOD FOR THE DETERMINATION OF THE FIRST AND SECOND CMC IN CTAB SOLUTION BY RESONANCE RAYLEIGH SCATTERING TECHNOLOGY

ABSTRACT A new light scattering technology is shown for study of the chemical character of a surfactant system. The resonance Rayleigh scattering (RRS) intensities of hexadecyltrimethylammonium bromide (CTAB) aqueous solution in a series of concentration were measured directly by a RRS technology without any probe. The first and second CMC of CTAB aqueous solution are obtained from the intensity of RRS vs concentration of CTAB curve, which are 8.9 × 10−4 and 2.0 × 10−2 mol L−1. These determination results are in correspondence with the results reported. Therefore, this method is very convenient, rapid and accurate and can be used as a new technology for the determination of CMC values of surfactants.

Resonance Rayleigh scattering spectral characteristics of interaction of nucleic acids with some cationic surfactants and their analytical applications

In near neutral medium, the resonance Rayleigh scattering (RRS) intensities of an alone cationic surfactant and nucleic acid are very weak. However, when they combine with each other to form a complex, the RRS intensity of the solution is enhanced greatly. In this paper the reactions of five cationic surfactants with nucleic acids have been studied. The results show that the reaction conditions and RRS spectral characteristics of these reactions are similar, but their sensitivities are obviously different. Among them, the sensitivity of cetyldimethyl benzylammonium chloride (CDBAC) with an aryl and large molecular weight is the highest, while that of cetyltrimethylammonium bromide (CTAB) without aryl and with small molecular weight is the lowest. The detection limits for ctDNA and yRNA of the former are 6.6 and 29.4 ng·mL -1 , while that of the latter are 13.3 and 53.6 ng·mL -1 . The method has better selectivity and can be applied to the determination of trace amounts of nucleic acids. Furthermore, it is discovered in the investigation that not only the RRS intensity is related to the structure and molecular weight of the cationic surfactants, but also the change of the RRS intensity is closely related to the conformational change of nucleic acid. Therefore, the RRS method can be expanded to become a useful way to study the nucleic acid conformation.

Resonance Rayleigh scattering spectra for studying the interaction of heparin with some basic phenothiazine dyes and their analytical applications

In near neutral medium, binding of heparin with some basic phenothiazine dyes such as methylene blue (MB), Azure B or toluidine blue (TB) can result in a significant enhancement of resonance Rayleigh scattering (RRS) and appearance of a new RRS spectrum. Their maximum scattered wavelengths appear at 346, 338 and 329nm for MB, Azure B and TB, respectively. The optimum conditions of these reactions, the influencing factors and the relationship between the RRS intensity and the concentration of heparin have been investigated. A new method for the determination of trace amounts of heparin based on the RRS method has been developed. The methods exhibit high sensitivities, the detection limits for heparin are 9.0ngml−1 for MB, 14.5ngml−1 for Azure B and 26.0ngml−1 for TB. Among them the MB is the most sensitive and has better selectivity, so it was applied to the determination of heparin in heparin sodium injection samples with satisfactory results. The mechanisms of the effect are discussed.

Resonance Rayleigh Method for the Determination of Proteins with Orange G

In pH 0.6 - 2.0 HCl-sodium acetate buffer solution, proteins react with an acidic monoazo dye such as Orange G, Methyl Orange, Methyl Red and Orange IV to form a combination product. This results in a significant enhancement of resonance Rayleigh scattering (RRS) and a new RRS spectrum appears. Owing to the fact that Orange G-protein system is the most sensitive, it was taken as an example to study. The RRS spectral characteristics of its combination product and the optimum condition for the reaction were investigated. The intensity of RRS is directly proportional to the concentration of protein in the range of 0 - 5.0 microg/mL. The method has high sensitivity; its detection limits are 2.6 ng/mL for BSA, 3.4 ng/mL for HAS and 7.1 ng/mL for alpha-chymotrypsin, respectively. A new method for the determination of trace amounts of proteins on the basis of RRS spectra has been developed.

Resonance Rayleigh-scattering method for the determination of proteins with some monoazo dyes of chromotropic acid.

In a weak acid medium, protein reacts with a monoazo dye of chromotropic acid, such as Chromazol KS (CALKS), Acid Chrome Dark Blue (ACDB), Chrome Blue SE (CBSE), Acid Chrome Blue K (ACBK), Chlorophosphonazo I (CPAI), Arsennazo I (AAI) and Chromotrope 2R (CT2R), to form a combination product. This results in a significant enhancement of the resonance Rayleigh-scattering (RRS) intensity, and the corresponding RRS spectrum appears. The characteristics of the RRS spectra of the combination products and the optimum conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of protein in a certain range. The RRS methods have high sensitivity for the determination of protein, the detection limits for bovine serum albumin (BSA) are 10.0 - 30.2 ng/ml, and the sensitivity order is CALKS > AAI = CPAI > ACBK = CT2R > ACDB > CBSE. The selectivity for CALKS has been examined, and the method was applied to the determination of a microg amount of protein in a synthetic sample with satisfactory results.

Resonance Rayleigh scattering method for the determination of trace amounts of cadmium with iodide-basic triphenylmethane dye systems.

In dilute phosphoric acid solution, cadmium (II) reacts with a large excess of I- to form [CdI4]2- which reacts further with basic triphenylmethane dyes such as crystal violet (CV), ethyl violet (EV), methyl violet (MV), brilliant green (BG) or malachite green (MG) to form an ion-association complex. This results in a significant enhancement of resonance Rayleigh scattering (RRS) intensity and the appearance of new RRS spectra. The characteristics of RRS spectra of the ion-association complexes, the influencing factors and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of cadmium from 0 to 60 ng mL(-1) for EV and MV systems, 0 to 80 ng mL(-1) for CV system, and 0 to 100 ng mL(-1) for BG and MG systems. The methods exhibit high sensitivities and the detection limits for cadmium are between 0.35 and 2.00 ng mL(-1) depending on the different reaction systems. The new RRS method was applied to the direct determination of traces of cadmium in pure zinc and synthetic water samples.

Sensitive and simple determination of protein by resonance Rayleigh scattering with 4-azochromotropic acid phenylfluorone

At pH 0.5–1.8 the resonance Rayleigh scattering (RRS) spectrum of 4-azochromotropic acid phenylfluorone has a peak at 337 nm, and the RRS intensity is enhanced by small amounts of protein due to the binding interaction of protein and the dye. On the basis of this, a highly sensitive assay for protein is established. There are linear relationships between the enhancement of RRS intensity and the concentrations of bovine and human serum albumins over the range 0.2–4.0 mg l −1. The detection limits (3 σ) for bovine and human serum albumins are 68 and 75 ng ml −1, respectively. The method is characterized by high sensitivity, short reaction period, simplicity and good stability of the chemical system. The results for diluted human serum and urine obtained by this method with a relative standard deviations; of 1.7–2.8% ( n = 6), are consistent with those obtained by the Coomassie brilliant blue G–250 assay.

Resonance Rayleigh scattering method for the determination of trace amounts of cadmium with iodide–rhodamine dye systems

Resonance Rayleigh scattering (RRS) of cadmium(II)–iodide–rhodamine dye systems and their analytical application have been studied. In dilute phosphoric acid, rhodamine dyes such as rhodamine B (BRhB), ethylrhodamine B (ERhB), butylrhodamine B (BRhB) and rhodamine 6G (Rh6G) have characteristic RRS spectra and their maximum RRS wavelengths ( λ max) are at 575 nm for RhB, ERhB and BRhB, and 545 nm for Rh6G. In the presence of a large excess of I −, cadmium(II) forms [CdI 4] 2−, which further reacts with a rhodamine dye to form an ion-association compound. This results in significant enhancement of RRS intensity and the appearance of new spectra with λ max at 610 nm for RhB, ERhB and BRhB systems and 585 nm for the Rh6G system. The characteristics of the RRS spectra of the ion-association compounds, the affecting factors and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of cadmium in the range 0–1.0 μg/25 ml for all the systems. The methods have high sensitivities and the detection limits for cadmium are 0.60–1.26 ng ml −1 depending on the reaction system; the Rh6G system is the most sensitive. A new method for the determination of trace cadmium on the basis of RRS is described.

Resonance Rayleigh scattering for the determination of cationic surfactants with Eosin Y

Resonance Rayleigh scattering (RRS) of cationic surfactants–Eosin Y systems and their analytical application have been studied. In aqueous solution at pH 2∼3, Eosin Y reacts with a monomer of cationic surfactants (CS), such as Zephiramine (Zeph), tetradecylpyridinium bromide (TPB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC) and cetyltrimethylammonium bromide (CTMAB), to form an ion associate and a new RRS spectrum appears. The spectral characteristics of the five ion associates are similar and their maximum scattering wavelengths (λmax) are all at 313 nm. The intensity of RRS at λmax of the ion associate is directly proportional to the concentration of CS in the range of 0∼3.0 μg/25 mL. The technique has high sensitivity for the determination of CS; their detection limit is between 5.57 ng/mL and 7.60 ng/mL depending on the CS. In this case, most metal and non-metal ions, NH4 + and some anionic surfactants do not interfere, so that the method has a good selectivity. It can be applied to the determination of trace amounts of cationic surfactants in water samples.

Resonance Rayleigh scattering of chromium(VI)-iodide-basic triphenylmethane dye systems and their analytical application

Resonance Rayleigh scattering (RRS) of chromium(VI)-iodide-basic triphenylmethane dye (BPTMD) systems and their analytical applications have been studied. In dilute phosphoric acid solution in the presence of excess I −, chromium(VI) oxidizes I − producing I 2, which binds I − to form I − 3 and I − 3 further reacts with a basic triphenylmethane dye such as crystal violet (CV), ethyl violet (EV), malachite green (MG), brilliant green (BG) and iodine green (IG) to form an ion-association complex. This results in the significant enhancement of RRS intensity and the appearance of new RRS spectra. The characteristics of RRS spectra of the ion-association complexes, the affecting factors and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of chromium(VI) in the range 0–1.5 μg/25 ml for the CV system and 0–1.0 μg/25 ml for the other systems. The methods have very high sensitivity and the detection limits for Cr(VI) are 0.065–5.6 ng ml −1 depending on the different reaction systems; the CV system is the most sensitive. A new method for the indirect determination of trace chromium(VI) on the basis of RRS has been advanced.

Resonance Rayleigh Scattering for an Indirect Determination of Trace Amounts of Selenium(IV) with Iodide-Basic Triphenylmethane Dye Systems

The resonance Rayleigh scattering (RRS) spectra of selenium(IV)/iodide/basic triphenylmethane dye systems have been studied. Intense RRS appears when selenium(IV) reacts with iodide and a basic triphenylmethane dye, such as Crystal Violet (CV), Ethyl Violet (EV), Brilliant Green (BG), Malachite Green (MG) and Iodine Green (IG), to form an ion-association complex. The characteristics of the RRS spectra of the ion-association complexes and the suitable conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of selenium(IV) in the range 0 - 0.30 μg/25 ml for the CV and EV systems, and 0 - 0.40 μg/25 ml for other systems. The RRS methods have very high sensitivities for an indirect determination of selenium(IV); the detection limits are between 0.094 ng/ml and 0.86 ng/ml for different dye systems. A new way to determine trace amounts of selenium based on the RRS spectra of the ion-association complex has been developed.

Resonant Rayleigh Scattering for the Determination of Trace Amounts of Mercury (II) with Thiocyanate and Basic Triphenylmethane Dyes

Intense resonance Rayleigh scattering (RRS) appears when mercury (II) reacts with thiocyanate and a basic triphenylmethane dye (BTPMD), such as crystal violet (CV), ethyl violet (EV), brilliant green (BG), malachite green (MG) or indine green (IG), to form an ion-association complex of the type (BTPMD)2[Hg(SCN)4]. The characteristics of RRS spectra of the ion-association complexes and suitable conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of mercury (II) in the range of 0±2.0 μg/25 ml. The RRS methods have very high sensitivities for determination of mercury (II); their detection limits are between 1.68 ng/ml and 6.00 ng/ml on different dye systems. The effects of foreign ions and ways to improve the selectivity were studied. The new highly sensitive methods for the determination of trace amounts of mercury based on the RRS of the ion-association complexes have been developed.