UV detection system

Kizu, R., Yamamoto, T., Yokoyama, T., Tanaka, M. and Miyazuki, M. (1995) A sensitive derivatization/UV detection system for HPLC determination of antitumor divalent and quadrivalent platinum complexes. Chem. Pharm. Bull., 43, 108-114. 

A basic UV detection system consists of these three basic components ... 

The UV detection system like any man-made product, is subject to failure. These failures could be detector tube failures, electronic or wiring failures, or optical system failure or contamination. 

Pressure sensors are not suitable as explosion suppression systems in large obstructed areas, but the basic ultraviolet (UV) detection system available today as a fire detector is capable of being used as an explosion detector, providing the exploding fireball is in the cone of vision of one of the detectors within the first 75 milliseconds. The extinguishing agent used must make... 

For the majority of soils analysed a complete distribution of the LAS homologues by their alkyl chain length was obtained without serious matrix interferences. However, the fluorimetric detection system employed by two laboratories (A, C) was superior to the original UV detection system (lab B). 

Nevertheless, the detection limits with these devices are Impressive. With a noise level of 100 pA and a 50% yield, both of which can very easily be obtained, the detection limit in mass flow of an analyte reacting with k = 2 is (100%/50%)(1/2 10 10 ° = 10" mole/sec with a flow-rate of 10 ul/sec this corresponds to a 10" M.solution. A 100-pg amount of analyte in a peak volume of lOO pi will give a 5-10"9 M solution with a molecular weight of 200. For comparison, a UV detection system, even in favourable instances with a molar absorptivity of 10 1 mole cm and a noise level of 10 a.u. would need a 10" M solution for a signal equal in magnitude to the noise. 

Brenes et al. employed two HPLC variants one equipped with the UV detection system and proposed the other with electrochemical (EC) detection. An effectiveness test was simultaneously performed on the three most applicable extraction methods, SPE, LEE, and DMF (proposed) based on the treatment of the extracted oil with 2NHC1 followed by the analysis of phenols in the aqueous phase. The conclusion was that 15%-40% of phenols remained unextracted when the liquid/liquid extraction method was applied with 80% methanol. Solid phase extraction (C,g cartridge) succeeded in retaining most phenols in the cartridge, but the recovery yield from the sorbent material was low. However, the new extraction method, based on the use of V,V-dimethylformamide (DME) as an extraction solvent, achieved a complete extraction of phenols from oils. 

Usually more than two channels are required to determine the ideal quantification procedure, and the use of external and internal standards is the most highly recommended way of producing the calibration curve. The particular example of benzoic acid was taken to demonstrate how LOD was determined (analytical signal-to-noise ratio <2 1 Fig. 2) in combination with the low variability observed between replicate analyses. Fig. 2 also clearly illustrates the establishment of minimum and maximum concentrations in order to define the response linear range for each compound using the UV detection system involving single A. Comparative measurements were taken to... 

---