Use of an Imaging Spectrograph System with a Fiber Optical Sensor and Two Dimensional Cooled Ccd Detector For Solid Surface Room Temperature Phosphorescence of Pesticides

ABSTRACT

This paper presents a development of a fiber optic sensor for solid surface room temperature phosphorescence of pesticides. The system is based on an imaging spectrograph coupled with a cooled two-dimensional charge coupled device detector. An optimization approach using a different mode of reading out data, the effects of moisture in solid matrix phosphorescence and the effects of heavy atoms are discussed. Spectral characterizations on Whatman N⁰1 filter papers of Warfarin, Naptalam, and naphthalene-type pesticides were evaluated. Limits of detection at ng to pg levels were estimated for all compounds. Satisfactory reproducibility of measurements was observed. The standard addition method was used to determine concentrations of Warfarin and Naptalam pesticides present together in a mixture. Results obtained show the potential of the device for the quantitative analysis of environmental pollutants.     

The Effects of Salts on the Room-Temperature Fluorescence and Room-Temperature Phosphorescence of Tetrols on Filter Paper and Filter Paper with Silicone

Abstract

Several salts were investigated to enhance the room-temperature solid-matrix phosphorescence of the four stereoisomeric tetrols on filter paper. Thallium acetate was found to enhance the phosphorescence to the greatest extent, but it was necessary to prepare the thallium acetate in an acetic acid solution to achieve the maximum phosphorescence from the solid matrix. Also, thallium acetate essentially quenched the solid-matrix fluorescence of the tetrols. Without thallium acetate adsorbed on filter paper, strong room-temperature fluorescence signals were observed from the tetrols adsorbed on filter paper. With a new solid matrix, filter paper which contained silicone, no heavy-atom was needed to obtain strong phosphorescence from the adsorbed tetrols. In fact, the room-temperature fluorescence from the tetrols adsorbed on this type of filter paper was very strong. The room-temperature fluorescence gave a limit of detection in the sub-picogram range for one of the tetrols with the silicone treated filter paper.     

Molecular Luminescence of Some Benzoylbenzimidazoles and Related Benzimidazoles

Abstract

Benzimidazoles and benzoyl benzimidazoles show interesting native luminescence properties that can be used as additional methods for qualitative and quantitative work. A comparison is made between fluorescence emission in solution, fluorescence on filter paper, low temperature phosphorescence (77°K) and room temperature phosphorescence.     

12种嘌呤类化合物的滤纸基质室温燐光法研究

较为详细地研究了１２种嘌呤类化合物以滤纸为基质的室温燐光（ＲＴＰ）光谱特性与分子结构的关系，以及重原子效应和酸度效应对ＲＴＰ的影响。     

The effect of sample environment on the room-temperature phosphorescence of several polynuclear aromatic hydrocarbons

Room-temperature phosphorescence (r.t.p.) of numerous molecules has been studied with emphasis on several polynuclear aromatic hydrocarbons (PAH). The heavy atom effect has led to a significant enhancement of r.t.p. signals for the PAH studied with the trend being Tl⁺ > Ag⁺ > Pb²⁺ > Hg²⁺. The Tl⁺ also resulted in enhanced spectral features of emission bands. R.t.p. could be induced from PAH on a sodium acetate sample support as well as on filter paper. A study of the effect of different gaseous environments provided anomalous results.     

激光诱导时间分辨光谱技术研究胶束体系中荧蒽的室温燐光行为

在胶束体系中 光衰减符合一级指数衰减公式Ｐｔ＝Ｐｏｅ－ｔ／ｒ，作者以激光诱导时间分辨光谱技术测量了ＳＤＳ胶束中荧蒽的燐光寿命和瞬时燐光强度产。值。提出Ｐｏ可定性表示重原子效应对燐光体经Ｓ１－Ｔ１系间跃迁几率的影响．而ｔ值表示三线态失活几率大小，即反映了胶束对燐光体的保护作用。作者详细研究了ＴＩＮＯ３用量、ＳＤＳ用量、ｐＨ值、Ｎａ２ＳＯ３用量对上述参数的影响，以期说明胶束增稳室温燐光法中影响燐光行为的各种因素的作用本质。     

4—甲基—7—羟基香豆素的发光特性研究

对比考察了多种溶剂介质中不同浓度４－甲基－７－羟基香豆素溶液的荧光光谱特性，发现其谱形状与峰位不仅随溶剂性质而异，且随浓度而变，在某些氢键溶剂中，激发光谱随浓度有很大变化，且发射光谱间存在某种内在联系。基于溶剂本身的性质及４－甲基－７－羟基香豆素在氢键溶剂中的二聚作用讨论了这种现象，本文还考察了这种香豆素衍生物在滤纸及聚酰胺膜基质上，以Ｐｂ（Ａｃ）２或Ｐｂ（ＮＯ３）２作重原子微扰剂时的室温磷光特性     

Room Temperature Phosphorescence Optosensor for Terbium

Abstract

A solid surface room temperature phosphorescence optosensing method has been developed for the determination of terbium(III) based on the adsorption of its binary complex with 1,4-bis (l'-phenyl-3′-methyl-5′-pyrazolone-4′-) butanedione-(1,4) (BPMPBD) onto the hydrogen form of a strong cation exchange resin packed in a flow cell in an aqueous flow system. The phosphorescence intensity is a linear function of the concentration of terbium in the range of 8x10^?9 M-6x10^?7 M, and the detection limit is 3x10^?9 M terbium. The response mechanism was also studied. The present optosensor has been used for the determination of trace amounts of terbium in synthetic samples with satisfactory results.     

罗丹明和荧光素类染料的固体基质室温燐光研究

研究了13种吨染料在滤纸基质上的室温燐光（RTP）性质。发现具有重原子取代基的荧光素本身能有较强的RTP发射。若以Ph（AC）2为重原子微扰剂，则所有染料均能产生不同强度的RTP信号。探讨了取代基对RTP发射的影响，测定了它们的RTP寿命。     

Polymerisation of styrene in microemulsion with catanionic surfactant mixtures

The use of aqueous catanionic surfactant mixtures in the oil-in-water (o/w) microemulsion polymerisation of styrene is reported. Catanionic surfactant mixtures of dodecyltrimethylammonium bromide 1 and sodium dodecylsulfate 3, or decanediyl-1,10-bis(dimethyldodecylammonium bromide) 2, a gemini surfactant, and the anionic surfactant 3 were used. Phase behaviour and polymerisation properties of the microemulsions were studied as a function of the total surfactant concentration and the cationic/anionic surfactant ratio. Single-phase o/w microemulsions were only formed if either the cationic or anionic surfactant were present in large excess. Upon -irradiation, polymer nanoparticles were obtained. Using dynamic light scattering, the particle radii were determined to be 10 to 20 nm, the size depending on the total surfactant concentration, the cationic/anionic surfactant ratio and the surfactant/styrene ratio. Size exclusion chromatography indicated molecular weights of polystyrene of between 3×10⁵ and 1.4×10⁶ Daltons. Catanionic 1/3 and 2/3 mixtures differ in their styrene solubilizations. In a 1- or 3-rich system, the solubilization efficiency can be improved by increasing the concentration of the oppositely charged minor surfactant component, while in a 2-rich system the addition of 3 only diminishes the efficiency. Possible reasons for the different behaviours are discussed.     

The Analysis of Theophylline — Containing Pharmaceuticals by Room Temperature Phosphorescence

Abstract

A simple and specific technique is used in analyzing pharmaceutical preparations (capsules, elixirs, syrups, and tablets) for theophylline and related compounds. The procedure consists of dissolving (diluting) appropriate amounts of the preparations and standards in (with) a 1 M KI-water solution, spotting 5 μL of each resultant solution onto filter paper discs, determining the phosphorescence intensities at room temperature and comparing sample signal levels to those of standards. The quantities of active ingredients and standards used in the determinations ranged from 25 ng to 1 μg. The results indicate that room temperature phosphorescence is useful for analyzing pharmaceutical preparations where active ingredients are usually contained in a wide variety of matrices.     

Determination of photophysical rate constants for the non-protected fluid room temperature phosphorescence of several naphthalene derivatives.

The determination of kinetic parameters for luminescence processes is very important in understanding the phosphorescence process and the mechanisms of the heavy atom effect (HAE). In our previous work, we reported that room temperature phosphorescence (RTP) emission of many naphthalene derivatives can be induced directly from their aqueous solution without using any kind of protective medium, and the name Non-Protected Fluid Room Temperature Phosphorescence (NP-RTP) is suggested for this new type of RTP emission. In order to further understand this kind of luminescence phenomenon, the influence of heavy atom perturber (HAP) concentration on RTP lifetime of several naphthalene derivatives was studied in detail in this paper. The possibility of determination of photophysical parameters for emission of NP-RTP was explored based on the definition on the phosphorescence lifetime and the relation with the concentration of HAP in this paper. A static Stern-Volmer equation for phosphorescence was derived and the luminescence kinetic parameters were calculated. The results obtained by two different ways proved that photophysical parameters for RTP emission can be determined based on the changes of the RTP lifetime.     

Study of Six Polycyclic Aromatic Hydrocarbons by Chemical Deoxygenation Microemulsion-Stabilized Room Temperature Phosphorimetry

Six polycyclic aromatic hydrocarbons (PAHs) are studied by chemical deoxygenation microemulsion-stabilized room temperature phosphorimetry with sodium sulfite as an oxygen scavenger and thallous nitrate as a heavy atom perturber in sodium dodecyl sulfate medium. Several factors influencing room temperature phosphorescence such as the concentration of sodium dodecyl sulfate, the heavy atom concentration, the pH, and the concentration of sodium sulfite are discussed and the quenching effect of NO₂⁻on room temperature phosphorimetry of PAHs was compared in the microemulsion and micelle media.     

A metal-free 2D layered organic ammonium halide framework realizing full-color persistent room-temperature phosphorescence

Organic–inorganic hybrid metal halides have attracted intensive attention because of their unique electronic structure and solution processability. They have a rigid micro/nano-structure and heavy atom effect, which has obvious advantages in promoting organic room temperature phosphorescence (RTP). However, the toxicity of heavy metals has limited their further development. Herein, two metal-free 2D layered ammonium halides, homopiperonylammonium bromide and chloride (HLB and HLC), are described for the first time. Their layered structure consists of rigid inorganic ammonium halide laminates and neatly stacked organic layers. The rigid laminates and external heavy atom effect of halogen atoms make HLB and HLC produce green RTP. When phosphor guests with different triplet energies are doped into HLB, HLC, or phenylethylamine salt hosts, effective full-color and even white ultra-long RTP with phosphorescence quantum yield up to 18.7% and lifetime up to 1.7 s is realized through energy transfer between the host and guest. Due to the simple solution synthesis, 10 g-level doped layered organic ammonium halides with the same phosphorescence properties can be easily obtained. The information ink based on these doped halides and non-toxic ethanol solvent can form various patterns on filter paper. The fluorescence and phosphorescence of these patterns are sensitive to the excitation wavelength and acid–base vapor. Consequently, they can be applied to multiple complex anti-counterfeiting and fluorescence/phosphorescence dual-mode chemical sensors.

A kind of metal-free organic ammonium halides characterized by a unique 2D layered structure show colorful ultralong phosphorescence. Phosphorescent quantum yield (up to 19%) and lifetime (up to 1.7 s) can be tuned by doping with different phosphors.     

Determination of Morestan Residues in Water and Foodstuffs by Transmitted Room Temperature Solid Phase Spectrophosphorimetry

Abstract

A method for the determination of the pesticide morestan by means of transmitted room temperature solid phase spectrophosphorimetry has been developed. The method is based on the native phosphorescence showed by the morestan when it is fixed in a Whatman No 4 paper as a solid support. The excitation and emission wavelengths were 362 and 527 nm, respectively. The optimum phosphorescent emission was obtained when the delay time was 0.15 ms and the gate time 12.0 ms without need of a heavy atom. The linear dynamic range was between 0.1 and 1.0 μg.ml^?1, and the detection and quantification limits were 0.03 and 0.09 μg.ml^?1, respectively. The precision of the method, expressed as the relative standard deviation of ten samples at the 0.6 μg.ml^?1 concentration level, was 3.0%. The method was applied to the determination of the pesticide in different type of waters, potatoes and vegetables.     

Studies of cyclodextrin-enhanced room-temperature phosphorescence

The enhancement of room-temperature phosphorescence by α-, β- and γ-cyclodextrins in the presence of heavy atoms is described for p-aminobenzoic acid, anthracene and six of its derivatives, dibenzofuran and some other compounds. The sensitivity can be improved by treating the filter paper substrate with the cyclodextrin (preferably β-cyclodextrin) or by mixing the analyte with β-cyclodextrin prior to sample spotting on the substrate.     

Determination of trace arsenic(V) by catalytic solid substrate-room temperature phosphorescence quenching method

In the H2SO4 medium and in the presence of dodecylbenzene sulfonic acid sodiumsalt (DBS), dimethyl yellow (R) could emit strong and stable solid substrate room temperature phosphorescence (RTP) on filter paper. And NaIO4 could oxidize R to cause the RTP quenching. Arsenic(V) could catalyze the reaction of NaIO4 oxidizing R, which caused the RTP sharply quenching. The reducing value of phosphorescence intensity (△Ip) for the system with DBS is 3.3 times higher than that without DBS. Moreover, the△Ip is proportional to the concentration of As(V). Based on the facts above, a new RTP quenching method for the determination of trace As(V) has been established.     

以滤纸为基质室温磷光法测定痕量多环芳烃的研究

1 前言 固体基质室温磷光法(SS-RTP)是一种发展很快的微量技术与痕量分析相结合的新技术.SS -RTP法以其简便、快速、灵敏的特点在环境污染物及药物分析方面得到了广泛的应用 [1],尤其对于痕量多环芳烃的分析十分有效.文献报道过应用环糊精诱导室温磷光法 [2]和胶束增稳室温磷光法[3]测定的方法.本文用国产快速定量滤纸作固体基质,探讨了测定萘、苊和屈磷光发光的条件,建立了以滤纸为基质的测定痕量萘、苊和屈的SS-RTP法.     

Spectroscopy of conjugated polymers: phosphorescence and delayed fluorescence

We report on the observation of delayed fluorescence (DF) and phosphorescence (P) from films and dilute frozen solutions of various conjugated polymers of the PPP‐type. The materials differ with respect to the rotational freedom along the polymer backbone. Upon pulsed optical excitation into the S₁←S₀ transition of the materials, delayed emission occurs on a time scale of μs to ms in solid films at 80 K. The phosphorescence in dilute frozen solution decays monoexponentially with a radiative lifetime on the order of one second. The data analysis reveals that the DF is caused by recombination of geminate electron hole pairs rather than triplet‐triplet annihilation. This conclusion is supported by investigations of the response of the DF to an applied electric field.     

Surface Modification and Contact Interaction of Particles

Abstract

The effects of particle surface modification by ambient media and surfactant adsorption on the cohesive forces in the immediate contacts between individual particles have been studied with the CF (cohesive force) apparatus. The values of the free energy of interaction in direct coagulation contacts between particles of various types in liquids of different polarity and in the presence of various surfactants have been measured. They cover a broad range of several orders of magnitude; these interactions define the rheological properties of concentrated thixotropic systems and their stability with respect to peptization. A similar experimental technique has been used for studying active media influences on various physico‐chemical processes of particle bridging and formation of the phase contacts responsible for the mechanical properties of related solid structures and their resistance to fracture. The effect of the adsorption induced decrease in strength and durability of such porous structures with phase contacts and compact solids is considered.