Sigma-Aldrich

1-（2-吡啶偶氮）-2-萘酚 indicator grade; CAS Number: 85-85-8; EC Number: 201-637-9; Synonyms: 1-（2-吡啶偶氮）-2-萘酚; find Sigma-Aldrich-101036 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich

1-（2-吡啶偶氮）-2-萘酚 indicator grade | Sigma-Aldrich

1-（2-吡啶偶氮）-2-萘酚 indicator grade

1-（2-吡啶偶氮）-2-萘酚

Solvent extraction and spectrophotometric determination of metals with 1-(2-pyridylazo)-2-naphthol.

Spectrophotometric Investigation of Analytical Reagent 1-(2-Pyridylazo)-2-naphthol and Its Copper Chelate.

1-(2-Pyridylazo)-2-naphthol as possible analytical reagent.

A copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV-vis absorption at neutral pH in aqueous solution.

Highly selective and sensitive colorimetric probe for hydrogen sulfide by a copper (II) complex of azo-dye based on chemosensing ensemble approach.

The development of surface-enhanced Raman scattering (SERS) as a prospective analytical methodology for detection of metal ions was shown in recent years by several studies on metal complexes. In this work, 1-(2-pyridylazo)-2-naphthol (PAN) and its Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II) complexes were studied by FTIR, FT-Raman and surface enhanced Raman spectroscopies. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculations were performed using the hybrid B3LYP exchange-correlation functional for the PAN molecule and its bidentate complexes. The calculated MEP distributions indicated the atoms with highest electronegativity, the adsorption to the silver surface occurring through these atoms. Based on experimental and theoretical data we were able to identify unique and representative features, useful for the identification of each PAN-metal complex.

SERS and DFT investigation of 1-(2-pyridylazo)-2-naphthol and its metal complexes with Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II).

The present work is focused on the modification of multiwalled carbon nanotubes with a ligand, 1-(2-pyridylazo)-2-naphthol (PAN), and its potential application for the development of a new, simple and selective modified glassy carbon electrode for stripping voltammetric determination of Pb(II). The electrochemical method is based on closed circuit accumulation of lead ions onto a PAN-modified multiwalled carbon nanotube electrode from 0.1 mol L(-1) oxalate buffer solution (pH = 3.0) during 150 s at the potential of -0.9 V, following by differential pulse anodic stripping voltammetric determination in the range -0.9 to -0.35 V. The analytical curve for Pb(II) ions covers a linear range varying from 0.8 up to 220.4 microg L(-1). The limit of detection was found to be 0.1 microg L(-1), while the relative standard deviation (RSD) at 50.0 microg L(-1) was 1.8% (n = 5). Many of the coexisting ions had little or no effect on the determination of lead(II). The results suggest that the proposed method can be applied as a simple and efficient alternative technique for the determination of lead ions which has good accuracy in real samples such as natural waters and standard alloys. In addition, this method demonstrates the powerful application of carbon nanotubes in the field of mercury-free electrodes in voltammetric stripping analysis.

Multiwalled carbon nanotube modified with 1-(2-pyridylazo)-2-naphthol for stripping voltammetric determination of Pb(II).

A cloud point extraction (CPE) method for the preconcentration of ultra-trace chromium speciation in human serum samples prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. In this method, Cr(III) reacts with 1-(2-pyridylazo)-2-naphthol (PAN) yielding a hydrophobic complex, which is then entrapped in the surfactant-rich phase, whereas Cr(VI) remained in aqueous phase. Thus, separation of Cr(III) and Cr(VI) could be realized. Total chromium was determined after the reduction of Cr(VI) to Cr(III) by using ascorbic acid as reducing reagent. PAN was used not only as chelating reagent in CPE, but also as chemical modifier in GFAAS. Triton X-114 non-ionic surfactant had been used as an extraction medium. The main factors affecting CPE efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 83.5 was obtained for the preconcentration of Cr(III) with 10 mL solution. Under the optimal conditions, the detection limit of Cr(III) was 0.02 μg L⁻¹. The relative standard deviation was 2.6% for intra-day assay precision (n=7, c=10 ng mL⁻¹), values of recovery for chromium were from 92.0% to 94.7% for three samples. This method is simple, accurate, and sensitive and can be applied to determine ultra-trace chromium speciation in human serum.

Cloud point extraction combined with graphite furnace atomic absorption spectrometry for speciation of Cr(III) in human serum samples.

A preconcentration/separation procedure is presented for the solid phase extraction of trace cadmium and lead ions as their 1-(2-pyridylazo) 2-naphthol (PAN) chelates in environmental samples on Chromosorb-106 resin, prior to cadmium and lead determinations by atomic absorption spectrometry. The preconcentration procedure was optimized by using model solutions containing cadmium and lead ions. The influences of pH of the model solutions, amounts of PAN, eluent type and volume etc. were investigated. Also the effects of the matrix constituents of the samples were also examined. Separation of cadmium and lead from real samples was achieved quantitatively. The procedure presented was checked with the analysis of microwave-digested standard reference materials (IAEA-336 Lichen and SRM 1515 Apple leaves). The preconcentration procedure was applied for the lead and cadmium contents of the natural water samples, some salts with satisfactory results (recoveries >95%, relative standard deviations <8%).

Enrichment/separation of cadmium(II) and lead(II) in environmental samples by solid phase extraction.

A very simple and selective spectrophotometric method for simultaneous determination of Co(II) and Ni(II) by 1-(2-pyridylazo) 2-naphthol (PAN), in micellar media, using H-point standard addition method (HPSAM) is described. The ligand and its metal complexes (Co(II)-PAN and Ni(II)-PAN) were made water-soluble by the neutral surfactant Triton X-100, and therefore, no extraction with organic solvents was required. Formation of both the complexes was complete within 10 min at pH 9 (adjusted by ammonia buffer). The linear range was 0.10-2.00 microg ml(-1) for Co(II) and 0.05-1.50 microg ml(-1) for Ni(II). The relative standard deviation (R.S.D.) for the simultaneous determination of 0.50 microg ml(-1) each of Co(II) and Ni(II) was 2.32 and 3.13%, respectively. Interference effects of common anions and cations were studied and the method was applied to simultaneous determination of Co(II) and Ni(II) in alloy samples. The method was compared with derivative spectrophotometric method.

H-point standard addition method for simultaneous spectrophotometric determination of Co(II) and Ni(II) by 1-(2-pyridylazo)2-naphthol in micellar media.

A simple approach to sensor development based on encapsulating a probe molecule in a cellulose support followed by regeneration from an ionic liquid solution is demonstrated here by the codissolution of cellulose and 1-(2-pyridylazo)-2-naphthol in 1-butyl-3-methylimidazolium chloride followed by regeneration with water to form strips which exhibit a proportionate (1 : 1) response to Hg(II) in aqueous solution.

Sensor technologies based on a cellulose supported platform.

Solidified floating organic drop microextraction (SFODME), combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for simultaneous separation/enrichment and determination of trace amounts of nickel and cobalt in surface waters and sea water. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of PAN, extraction time, stirring rate, extraction temperature, sample volume and nature of the solvent were optimized. Under the optimum experimental conditions, a good relative standard deviation for six determination of 20 ng l(-1) of Co(II) and Ni(II) were 4.6 and 3.6%, respectively. An enrichment factor of 502 and 497 and detection limits of 0.4 and 0.3 ng l(-1) for cobalt and nickel were obtained, respectively. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

Solidified floating organic drop microextraction (SFODME) for simultaneous separation/preconcentration and determination of cobalt and nickel by graphite furnace atomic absorption spectrometry (GFAAS).

An automatic on-line pre-concentration system is proposed for lead determination in drinking water using flame atomic absorption spectrometry (FAAS). Lead(II) ions are retained as the 1-(2-pyridylazo)-2-naphthol (PAN) complex in the walls of a knotted reactor, followed by an elution step using 0.50molL(-1) hydrochloric acid solution. Optimisation involving the sampling flow rate, pH and buffer concentration factors was performed using a Box-Behnken design. Other factors were established considering results of previous experiments. The procedure allows the determination of lead with a 0.43microgL(-1) detection limit (3sigma/S) and precisions (expressed as relative standard deviation) of 4.84% (N=7) and 2.9% (N=7) for lead concentrations of 5 and 25microgL(-1), respectively. The accuracy was confirmed by the determination of lead in the NIST SRM 1643d trace elements in natural water standard reference material. The pre-concentration factor obtained is 26.5 and the sampling frequency is 48h(-1). The recovery achieved for lead determination in the presence of several ions demonstrated that this procedure could be applied to the analysis of drinking water samples. The method was applied for lead determination in drinking water samples collected in Jequié City, Brazil. The lead concentration found in 25 samples were always lower than the permissible maximum levels stipulated by World Health Organization.

Automatic on-line pre-concentration system using a knotted reactor for the FAAS determination of lead in drinking water.

A simple, highly sensitive and environment-friendly method for the determination of trace amount of nickel ion in different matrices is proposed. In the preconcentration step, the nickel from 10 mL of an aqueous solution was extracted into 500 microL of ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C(4)MIM][PF(6)], containing PAN as complexing agent. Subsequently, the PAN complex was back-extracted into 250 microL of nitric acid solution, and 100 microL of it was analyzed by flow injection flame atomic absorption spectrometry (FI-FAAS). The main parameter influencing the extraction and determination of nickel, such as pH, concentration of PAN, extraction time and temperature, ionic strength, and concentration of stripping acid solution, were optimized. An enhancement factor of 40.2 was achieved with 25 mL sample. The limit of detection (LOD) and quantification obtained under the optimum conditions were 12.5 and 41.0 microg L(-1), respectively. To validate the proposed methods two certified reference materials 681-I and BCR No. 288 were analyzed and the results were in good agreement with the certified values. The proposed method was successfully applied to determination of nickel in water samples, rice flour and black tea.

A novel ionic liquid/micro-volume back extraction procedure combined with flame atomic absorption spectrometry for determination of trace nickel in samples of nutritional interest.

More effective rotavirus vaccines are essential for preventing extensive diarrheal morbidity and mortality in children under five years of age in low-resource regions. Nonreplicating rotavirus vaccines (NRRV) administered parenterally provide an alternate vaccination method to the current licensed oral vaccine. Live attenuated vaccines and may generate increased efficacy in low-resource settings because the parenteral administration route bypasses some of the challenges associated with oral administration, including differences in intestinal environments. Work described here supports development of a trivalent NRRV vaccine for parenteral administration to avoid complications of the gastrointestinal route. Recombinant VP8* subunit proteins representing some of the most prevalent strains of rotavirus infecting humans - DS-1 (P[4]), 1076 (P[6]), and Wa (P[8]) - were combined with an aluminum adjuvant and the P2 epitope of tetanus toxoid to enhance the immune response to this NRRV antigen. Vaccine formulation development included selection of aluminum hydroxide (Alhydrogel®) as an appropriate adjuvant as well as an optimal buffer to maintain antigen stability and optimize antigen binding to the adjuvant. Characterization assays were used to select the lead vaccine formulation and monitor formulation stability. The NRRV liquid formulation was stable for one year at 2°C to 8°C and four weeks at 37°C. Immunogenicity of the NRRV formulation was evaluated using a guinea pig model, where we demonstrated that the adjuvant provided a 20-fold increase in neutralization titer against a homologous antigen and that the P2-fusion also enhanced the serum neutralizing antibody responses. This vaccine candidate is currently being evaluated in human clinical trials.

Formulation and preclinical studies with a trivalent rotavirus P2-VP8 subunit vaccine.

This paper presents the development, characterization and quality control of analytical methods based on the use of disposable optical sensors for determination of heavy metals. Chromogenic reagents such as 1-(2-pyridylazo)-2-naphthol, (2-pyridylazo)resorcinol, Zincon, Ferrozine, and Chromazurol S were used to develop optical sensors of heavy metal ions found as contaminants in pharmaceutical substances and products, such as Zn(II), Cu(II), Ni(II), Fe(II), and Fe(III). The chromogenic reagents were immobilized in polymeric membranes by spin-coating from cocktails containing all reagents needed. The methods were prevalidated using a comprehensive quality control strategy based on a system of mathematical/statistical testing and diagnosis of each prevalidation step. This system involved characterization of analytical groups; checking of two limiting groups; testing of data homogeneity; recognition of outliers; and determination of analytical functions, limiting values, precision and accuracy. The prevalidation strategy demonstrated the reliability of the proposed method and pointed out some limitations. Combining the optical sensors with multicomponent linear regression allowed simultaneous determination of multiple metals in synthetic mixtures with different compositions. Good agreement between experimental and theoretical amounts of heavy metals in the mixtures was obtained for the majority of sensors and metals. Even better agreement was obtained between the experimental and theoretical total amounts of metals in the mixtures. The proposed analytical methods were successfully applied to the determination of zinc in pharmaceutical preparations of insulin and the determination of metal mixtures in a commercial nasal spray of isotonic seawater. The reliable and sensitive individual optical sensors developed in this study may be useful for designing a multimembrane optical tongue that with appropriate further optimization can be used for screening heavy metals in various matrices.

Characterization of disposable optical sensors for heavy metal determination.

A new micelle-mediated separation and preconcentration method was developed for ultra-trace quantities of mercury ions prior to spectrophotometric determination. The method is based on cloud point extraction (CPE) of Hg(II) ions with polyethylene glycol tert-octylphenyl ether (Triton X-114) in the presence of chelating agents such as 1-(2-pyridylazo)-2-naphthol (PAN) and 4-(2-thiazolylazo) resorcinol (TAR). Hg(II) ions react with both PAN and TAR in a surfactant solution yielding a hydrophobic complex at pH 9.0 and 8.0, respectively. The phase separation was accomplished by centrifugation for 5 min at 3500 rpm. The calibration graphs obtained from Hg(II)-PAN and Hg(II)-TAR complexes were linear in the concentration ranges of 10-1000 μg L(-1) and 50-2500 μg L(-1) with detection limits of 1.65 and 14.5 μg L(-1), respectively. The relative standard deviations (RSDs) were 1.85% and 2.35% in determinations of 25 and 250 μg L(-1) Hg(II), respectively. The interference effect of several ions were studied and seen commonly present ions in water samples had no significantly effect on determination of Hg(II). The developed methods were successfully applied to determine mercury concentrations in environmental water samples. The accuracy and validity of the proposed methods were tested by means of five replicate analyses of the certified standard materials such as QC Metal LL3 (VWR, drinking water) and IAEA W-4 (NIST, simulated fresh water).

Cloud point extraction and spectrophotometric determination of mercury species at trace levels in environmental samples.

Planar triazinium cationic species from vanadyl-assisted cyclization of 1-(2-thiazolylazo)-2-naphthol (H-TAN, 1), 1-(2-pyridylazo)-2-naphthol (H-PAN, 2), 2-(2'-thiazolylazo)-p-cresol (H-TAC, 3) and 6-(2'-thiazolylazo)-resorcinol (H-TAR, 5) were prepared and characterized. A dioxovanadium(V) species [VO(2)(TAR)] (4) was also isolated. Compounds 1, 2 and 4 were structurally characterized. Both 1 and 2 have planar structures. Complex 4 has V(V)O(3)N(2) coordination geometry. The cyclised triazinium compound forms a radical species within -0.06 to -0.29 V vs. SCE in DMF-0.1 M tetrabutylammonium perchlorate with a second response due to formation of an anionic species. A confocal microscopic study showed higher nuclear uptake for 1 having a fused thiazole moiety than 2 with a fused pyridine ring. The compounds showed a partial intercalative mode of binding to calf thymus DNA. Compound 1 showed plasmid DNA photo-cleavage activity under argon and photocytotoxicity in HeLa and MCF-7 cells with IC(50) values of 15.1 and 3.4 μM respectively in visible light of 400-700 nm, while being essentially non-toxic in the dark with IC(50) values of 90.4 and 21.9 μM. A TDDFT study was done to rationalize the experimental data.

1-（2-吡啶偶氮）-2-萘酚

indicator grade

属性

质量水平

等级

形式

technique(s)

颜色

mp

λ_max

SMILES string

InChI

InChI key

说明

一般描述

包装

安全信息

储存分类代码

WGK

闪点(F)

闪点(C)

个人防护装备

文件

分析证书

原产地证书 (CofO)

更多文件

Quotes and Ordering

同行评审论文

技术服务

支持

订单

公司

社交媒体

Merck

1-（2-吡啶偶氮）-2-萘酚

indicator grade

属性

质量水平

等级

形式

technique(s)

颜色

mp

λmax

SMILES string

InChI

InChI key

说明

一般描述

包装

安全信息

储存分类代码

WGK

闪点(F)

闪点(C)

个人防护装备

文件

分析证书

原产地证书 (CofO)

更多文件

Quotes and Ordering

同行评审论文

技术服务

支持

订单

公司

社交媒体

Merck

λ_max