Development and validation of a rapid HPLC method for the determination of five banned fat-soluble colorants in spices using a narrow-bore monolithic column

This work reports a fast and simple liquid chromatographic method for the simultaneous determination of five banned fat-soluble synthetic colorants, namely Sudan I-IV and Para-Red, in spice samples. The analytes were successfully separated isocratically in less than 5 min on the new narrow bore monolithic column, FastGradient^® Chromolith (50 mm × 2.0 mm i.d.) using a mobile phase of 0.1% (v/v) HCOOH/acetonitrile (35/65%, v/v) at a flow rate of 1.5 mL min⁻¹. All colorants were detected at 506 nm. The main parameters (mobile phase composition, flow rate, injection volume) affecting the separation were studied. The proposed method was thoroughly validated in terms of linearity, LODs, precision and accuracy. The method was applied to the determination of the studied azo-dyes in various spices (paprika, chilli and mixed spice powders) after ultrasound-assisted extraction. Satisfactory recoveries, ranging from 92% to 109% were obtained.     

甲酚红褪色分光光度法测定芬布芬的研究及其应用

在pH9.00的tris-HCl缓冲溶液中,甲酚红与芬布芬反应形成离子缔合物,使甲酚红溶液褪色.实验结果表明:最大褪色波长位于569.0nm,芬布芬浓度在0.05086～10.17μg/mL范围内遵循比尔定律,回归方程为ΔA=0.1702c+0.0107(c=μg/mL),相关系数为r=0.9996,表观摩尔吸光系数为4.537×104 L·mol-1·cm-1.据此建立了测定药物制剂和生物样品中芬布芬含量的褪色分光光度法,样品测定平均回收率为97.97%～101.6%.     

Insight into Amyloid Formation Using Congo Red as the Electrochemical Probe

The amyloid‐β (Aβ) aggregation pathway is an important target for the discovery of drugs that can prevent or delay the onset of Alzheimer’s disease (AD). The electrochemistry of Congo Red (CR) represents a particularly promising tool for screening of Aβ‐binding therapeutics in a rapid and cost‐effective format. The results of the differential pulse voltammetry (DPV) measurements were confirmed using simultaneous UV‐vis analysis of the same incubated Aβ samples. The early changes in the electrochemical signals were attributed to the interaction of the Aβ oligomers with CR. The electrochemical approach, in principle, allowed monitoring small molecule‐Aβ interactions on the time scale of aggregation.     

Synthesis and characterization of Eu doped SrY2O4 phosphor

The present paper reports that TL glow curve and kinetic parameter of Eu³⁺ doped SrY₂O₄ phosphor irradiated by beta source. Sample was prepared by solid state preparation method. Sample was characterized by XRD analysis and particle size was calculated by Debye–Scherrer formula. The sample was irradiated with Sr-90 beta source giving a dose of 10 Gy and the heating rate used for TL measurements are 6.7 °C/s. The samples display good TL peaks at 106 °C, 225 °C and 382 °C. The corresponding kinetic parameters are calculated. The photoluminescence excitation spectrum at 247 and 364 nm monitored with 400 nm excitation and the corresponding emission peaks at 590, 612 and 624 nm are reported.     

UV/Vis光谱法研究红子色素的稳定性

本文报导了从红子提取，分离天然色素及酸碱和温度等对该色素稳定性的影响。     

绿色ACEL粉末材料的晶体粒度对发光性能的影响

目前粉末ＡＣＥＬ器件有三类：玻璃屏、塑料软屏和搪瓷屏．目前商品化的电致发光材料，每炉料大约在１００～２００克之间，粒度在１０μｍ左右，不能满足产业化的需求．影响发光材料亮度、寿命、粒度的主要因素有Ｃｕ的浓度、灼烧时间、退火方式和灼烧气氛［１，２，３］...     

Unsteady-state methods of investigation of the heterogeneous chemiluminescence of phosphor crystals

Priazovskii State Technical University, Pereulok Respubliki 7, Mariupol 341000, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 3, pp. 210–214, May–June, 1995.     

Bestimmung von Arsen in Blei und Bleilegierungen

Zusammenfassung Es wird ein Verfahren zur Bestimmung von g/g- bis mg/g-Gehalten Arsen in Blei und Bleilegierungen beschrieben. Das Arsen wird dazu mit NaBH₄ als AsH₃ aus der Probenlösung ausgetrieben und atomabsorptions-spektrometrisch in einer geheizten Quarzküvette bestimmt. Durch geeignete Arbeitsbedingungen werden Störungen durch die Matrix ausgeschaltet. Für den gesamten Arbeitsbereich beträgt die relative Standardabweichung etwa 3% (N=12); die Nachweisgrenze (3 -Grenze) wurde zu 0,1 g/g As ermittelt.

---

Determination of arsenic in lead and lead alloys

Summary A method is described for the determination of g/g to mg/g concentrations of As in lead and lead alloys. For that purpose arsenic is blown out from the sample solutions as AsH₃ by use of NaBH₄ and determined by AAS in a heated quartz cuvette. Using suitable conditions disturbances caused by the matrix are eliminated. The relative standard deviation over the whole working range is about 3% (N=12); the detection limit (3 ) was found to be 0.1 g/g As.

     

Luminescence in ZnS: La and ZnS: (Mn,La) phosphors

The photo (PL) and electro (EL) luminescence in ZnS: MnLa and ZnS: La have been studied. The enhancement and quenching of emission bands have been observed on the simultaneous application of sinusoidal field and photons. The wave shape, voltage, frequency and temperature dependence of EL brightness have been reported. A study of the phosphorescence and thermoluminescence of these phosphors is also carried out and it is observed that the trap-depth changes slowly with temperature and activator concentration. An attempt has been made to calculate the trap depth by studying temperature dependence of EL brightness. The results are reported and discussed.     

Application de la Spectroscopie Infra Rouge à L'étude du Comportement Thermique de la Cellulose Partie I.

In this work, we describe and evaluate the use of the Fourier transform infra red (FTIR) spectroscopy in DRIFT mode (diffuse reflectance infra red Fourier transform) in an environmental device to follow the functional evolution of cellulose during thermal treatments. The potentialities (and difficulties) of the technic are given. This revised version was published online in July 2006 with corrections to the Cover Date.