1.1 This test method employs the signal-to-noise ratio theory to determine the sensitivity of a fluorescence measuring system in testing for the limit of detection (LOD) of quinine sulfate. The results obtained with quinine sulfate are suitable for specifying instrument performance on samples having excitation and fluorescence bands wider than 10 nm.

1.1.1 This test method is not intended to be used as (1) a rigorous test of performance of instrumentation, or (2), to intercompare the quantitative performance of instruments of different design.

1.2 This test method has been applied to fluorescence-measuring systems utilizing continuous and low-energy excitation sources (for example, an excitation source of 150-W electrical input or less). There is no assurance that extremely intense illumination will not cause photodecomposition of the compound suggested in this test method. For this reason, it is recommended that this test method not be indiscriminately employed with high intensity light sources. This test method is not intended to determine minimum detectable amounts of other materials. If this test method is extended to employ other chemical substances, the user should be aware of the possibility that these other substances may undergo decomposition or adsorption onto containers.

1.3 The practical lower limit of this test method is 1 ng of quinine sulfate per mL (one part per billion; 1 ppb).

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.