Fluorescence performance verification

The USP 24/NF 19, section 201 (Ref.f p. 1856), contains a general TLC identification test that involves a non-high-performance silica gel layer with fluorescent indicator, chloroform-methanol-water (180 15 1) mobile phase, and detection under 254 nm UV light for verification of the identities of compendial drugs in dosage form test solutions prepared according to the individual monographs. Section 621 of the USP 24/NF 19 (Ref. pp. 1916-1917) presents brief information... 

As with spectrophotometers, NIST provides a number of SRMs for use in the calibration or verification of the performance of fluorometers or fluorospectrophotometers. These include SRM 936a (quinine sulfate dihydrate) for calibrating such instruments and SRM 1932 (fluorescein) for establishing a reference scale for fluorescence measurements (see http //www.nist.gov). 

In recent years, a new approach to condensed-phase spectroscopy has emerged, that focuses on the spectral properties of a single molecule (SM) embedded in a condensed phase [14], Thanks to experimental advances made in optics and microscopy [5], it is now possible to perform single molecule spectroscopy (SMS) in many different systems. Motivations for SMS arise from a fundamental point of view (e.g., the investigation of the field-matter interaction at the level of a SM and the verification of statistical assumptions made in ensemble spectroscopy) and from the possibility of applications (e.g., the use of SMS as a probe for large biomolecules for which a SM is attached as a fluorescent marker). 

Matrix RMs representing, as much as possible, the matrix to be analyzed and being characterized or certified for given parameters (e.g., concentrations of chemical substances). They consist of samples with a natural matrix, unknown or partially known, which are primarily used for the verification of a measurement process (CRMs) and/or the evaluation of laboratory performance in the framework of interlaboratory testing schemes (RMs). These materials may be used for the calibration of certain types of measuring instruments (i.e., techniques that require calibration with a material similar to the matrix analyzed, e.g.. X-ray fluorescence (XRF)). 

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