Purpose
These materials may be used on a routine basis to calibrate, compare and monitor the performance of Fluorescence Spectrophotometers. p-Terphenyl, Ovalene, Tetraphenylbutadiene and Anthracene in PMMA are cited in USP chapter for wavelength validation.
Description and Discussion
Six polymer blocks containing seven fluorescent compounds whose spectra cover a broad spectral range with excitation range from 260 to 600nm and emission range from 370 to 630 nm. This wide spectral range enables the user to select a reference material with broadly similar spectral properties to those of the analyte, ensuring a reasonable spectral overlap and measurable signals without changing important parameters such as slit widths and wavelength settings.
REF NO | COMPOUND | APPROXIMATE MOLAR CONCENTRATION | PEAK EXCITATION WAVELENGTH (NM) | EXCITATION RANGE (NM) | PEAK EMISSION WAVELENGTH (NM) | EMISSION RANGE (NM) |
1 | Anthracene | 1 x 10-5 | 360 | 260 - 320 | 402 | 370 - 470 |
Naphthalene | 6 x 10-5 | 290 | 290 - 390 | 330 | 310 - 400 | |
2 | Ovalene | 2 x 10-7 | 342 | 300 - 460 | 482 | 450 - 570 |
3 | p-Terphenyl | 5 x 10-7 | 295 | 270 - 350 | 338 | 310 - 410 |
4 | Tetraphenylbutadiene | 3 x 10-7 | 348 | 290 - 390 | 422 | 370 - 540 |
5 | Compound 610 | 1 x 10-6 | 440 | 360 - 490 | 475 | 420 - 570 |
6 | Rhodamine | 2 x 10-7 | 562 | 500 - 600 | 573 | 530 - 630 |
The solid polymethyl methacrylate (PMMA) matrix provides a stable environment for the fluorescent compounds. Being solids, there can be no evaporation of solvents, providing long term stability.