Phosphorimetry

Vo-Dinh, T. Room-Temperature Phosphorimetry for Chemical Analysis. Wiley-Interscience New York, 1984. 

Fluorometry and Phosphorimetry. Modem spectrofluorometers can record both fluorescence and excitation spectra. Excitation is furnished by a broad-band xenon arc lamp foUowed by a grating monochromator. The selected excitation frequency, is focused on the sample the emission is coUected at usuaUy 90° from the probe beam and passed through a second monochromator to a photomultiplier detector. Scan control of both monochromators yields either the fluorescence spectmm, ie, emission intensity as a function of wavelength X for a fixed X, or the excitation spectmm, ie, emission intensity at a fixed X as a function of X. Fluorescence and phosphorescence can be distinguished from the temporal decay of the emission. 

Samples are usually in solution, but soHds (often fro2en solutions) yield narrow-line spectra that are useful in distinguishing components of mixtures. In phosphorimetry soHd sampling may be necessary to minimi2e quenching processes. 

R. J. Hurtubise, Phosphorimetry Theory, Instrumentation, and Applications, VCH Pubhshers, New York, 1990. 

In 1944, Lewis and Kasha (52) identified phosphorescence as a forbidden" transition from an excited triplet state to the ground singlet state and suggested the use of phosphorescence spectra to identify molecules. Since then, phosphorimetry has developed into a popular method of analysis that, when compared with fluorometry, is more sensitive for some organic molecules and often provides complimentary information about structure, reactivity, and environmental conditions (53). 

This chapter describes use of solid-surface room temperature phosphorimetry (SSRTP) as a detection technique in the liquid chromatographic (LC) analysis of caffeine, theophylline, and theobromine. Measurements were made in a continuous mode, using a 2-nebulizer automatic system for SSRTP analysis (previously optimized for LC detection). Use of SSRTP and UV absorption detection was compared under identical experimental conditions.38... 

Vol. 66 Solid Phase Biochemistry Analytical and Synthetic Aspects. Edited by William H. Scouten Vol. 67 An Introduction to Photoelectron Spectroscopy. By Pradip K. Ghosh Vol. 68 Room Temperature Phosphorimetry for Chemical Analysis. By Tuan Vo-Dinh Vol. 69 Potentiometry and Potentiometric Titrations. By E. P. Serjeant Vol. 70 Design and Application of Process Analyzer Systems. By Paul E. Mix Vol. 71 Analysis of Organic and Biological Surfaces. Edited by Patrick Echlin Vol. 72 Small Bore Liquid Chromatography Columns Their Properties and Uses. Edited by Raymond P.W. Scott... 

In 1962, Parker and Hatchard described a photoelectric spectrometer for phosphorescence measurements with which they were capable of obtaining phosphorescence spectra, and of determining lifetimes and quantum efficiencies of a large number of organic compounds. This work stimulated intensely the interest in the phosphorimetry of diverse chemical analytes [5], and one year later, Wine-... 

R. P. Fisher and J. D. Winefordner, Pulsed source-time resonance phosphorimetry, Anal. Chem. 44, 948-956 (1972). 

Asafu-Adjaye EB, Yun Jl, Su SY. 1985. Multi-component mixture analysis using room-temperature phosphorimetry. Anal Chem 57 904-907. 

R3. Rubin, M., Fluorometry and phosphorimetry in clinical chemistry. Advan. Clin. Chem. 13, 161-269 (1970). 

Fluorometry and Phosphorimetry in Clinical Chemistry Martin Rubin... 

Notwithstanding the excellent analytical features inherent in molecular phosphorimetric measurements, their use has been impeded by the need for cumbersome cryogenic temperature techniques. The ability to stabilize the "triplet state" at room temperature by immobilization of the phosphor on a solid support [69,70] or in a liquid solution using an "ordered medium" [71] has opened new avenues for phosphorescence studies and analytical phosphorimetry. Room-temperature phosphorescence (RTF) has so far been used for the determination of trace amounts of many organic compounds of biochemical interest [69,72]. Retention of the phosphorescent species on a solid support housed in a flow-cell is an excellent way of "anchoring" it in order to avoid radiationless deactivation. A configuration such as that shown in Fig. 2.13.4 was used to implement a sensor based on this principle in order to determine aluminium in clinical samples (dialysis fluids and concen-... 

T. VO-DINH, "Room Temperature Phosphorimetry for Chemical Analysis", Wiley, New York, 1984. 

A number of analytical techniques have been used for measuring aluminum concentrations in environmental samples. These include GFAAS, FAAS, NAA, ICP-AES, ICP-MS, spectrophotometry using absorbance and fluorescence detection, phosphorimetry, chromatography and gas chromatography equipped with an electron capture detector (GC/ECD) (Andersen 1987, 1988 Benson et al. 1990 ... 

De La Campa MRF, Garcia MED, Sanz-Medel A. 1988. Room-temperature liquid phosphorimetry of the aluminum-ferron chelate in micellar media-determination of aluminum. Anal Chim Acta 212 235-243. 

Murillo-Pulgarin et al. used a phosphorimetry method for the determination of dipyridamole in pharmaceutical preparations [44]. Ten tablets or capsules were powdered and homogenized, and then 0.1 g was dissolved in 0.1 M sodium dodecyl sulfate. The determination of dipyridamole was carried out in 26 mM sodium dodecyl sulfate/ 15.6 mM thallium nitrate/20 mM sodium sulfite, whose pH was adjusted to 11.5 by the addition of sodium hydroxide. After 15 min at 20°C, the phosphorescence was measured at 616 nm (after excitation at 303 nm). The calibration graph was linear from 100-1600 ng/mL, with a detection limit of 16.4 ng/mL. Relative standard deviations were in the range of 0.5-7.3%, and sample recoveries were in the range of 95-97%. 

The excited state acid-base behaviour of molecules has direct implications in the field of analytical fluorimetry and phosphori-metry. Since the emitting species can be changed by adjusting the acidity of the solution, the sensitivity or selectivity of an analytical procedure can be increased (see e.g. McCarthy and Winefordner, 1967 Argauer and White, 1970). Thus, for example, the limit of detection by phosphorimetry of 4-nitrophenol is much lower in solutions containing the anion (Schulman and Winefordner, 1970) and the long-wavelength fluorescence of warfarin in sulphuric acid allows its selective fluorimetric determination in the presence of other 4-hydroxycoumarins (Yakatan et al., 1972). 

Phosphorimetry, as an Analytical Approach in Biochemistry (Winefordner, McCarthy,... 

Water Wet-ashed reaction with complexant Pulsed-laser phosphorimetry 0.05 ppb 103 (average) ASTM 1994 (Method 5174-91)... 

Biological and environmental samples Complexation with phosphoric acid Laser phosphorimetry Sensitivity 10- g No data Bushaw 1984... 

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