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Quantitative Chromatographic Analysis
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| Specifications | Units |
| Dynamic Range | (DR) g/ml (e.g. 3 x 10-9 to 6 x 10-5 ) |
| Response Index | (r) dimensionless |
| Linear Dynamic Range | (DLR) g/ml (e.g. 1 x 10-8 to 2 x 10-5 ) |
| Detector Response | (RC) Volts/g or (specific units of measurement/g) |
| Detector Noise Level | (ND) usually in millivolts but may be in specific units (e.g. Refractive Index Units) |
| Sensitivity or minimum detectable concentration | (XD) g/ml (e.g. 3 x 10-8) but may be in specific units (e.g. Absorption Units) |
| Total Detection System Dispersion | ( |
| Cell Dimensions | (length (l), and radius (r)), (cm) |
| Cell Volume | (VD), ml. |
| Overall Time Constant (sensor and electronics) | (TD), seconds (sometimes milliseconds) |
| Pressure Sensitivity | (DP) usually in the USA, p.s.i in Europe MPa |
| Flow Rate Sensitivity | (DQ) usually in ml/min |
| Temperature Range | oC |
The former depends on the chosen column and phase system, the latter requires a detector with a known and predictable response and a sensitivity commensurate with the composition and size of the sample. Chromatographic detectors that are commercially available will all be suitable for quantitative analysis, but differ in their performance specifications.
The Dynamic Range of a Detector
The detector dynamic range extends from the minimum detectable concentration (i.e. the sensitivity) to that concentration where the detector no longer responds to any concentration increase. The dynamic range is not pertinent to quantitative chromatographic analysis, but is of interest in preparative chromatography. The dynamic range of a detector (DR) is usually given in the form
DR = 6 x 105
The dynamic range is dimensionless as it is a ratio of concentrations and, thus, independent of the units used.
