On-line dilution

Fig. 5.13 Schematic block diagram of continuous-flow on-line dilution system.

The use of discrete sample volumes to provide improved tolerance of the detector to dissolved solids, organic solvents and sample viscosity. FI provides on-line dilution and a suitable means of handling slurried samples. 

The contribution of flow analysis to improving the performance of atomic spectrometry is especially interesting in the field of standardisation. FIA can provide a faster and reliable method to relate the absorbance, emission or counts (at a specific mass number) to the concentration of the elements to be determined. In fact, flow analysis presents specific advantages to solving problems related to the sometimes short dynamic concentration ranges in atomic absorption spectrometry, by means of on-line dilution. The coupling of FI techniques to atomic spectrometric detectors also offers tremendous possibilities to carry out standard additions or internal standardisation. 

Hendricks, J., Navaline, K., and Di Bussolo, J. (2005). On-line dilution techniques to maximize analyte extraction from acetonitrile-rich samples in turbulent-flow LC-MS/MS systems. In Proceedings of the 53rd ASMS Conference on Mass Spectrometry and Allied Topics, San Antonio, TX. 

F. Albertus, B. Horstkotte, A. Cladera, V. Cerda, A robust multisyringe system for process flow analysis. Part I. On-line dilution and single point titration of protolytes, Analyst 124 (1999) 1373. 

D.A. Whitman, G.D. Christian, Cascade system for rapid on-line dilutions in flow-injection analysis, Talanta 36 (1989) 205. 

D.G. Themelis, A. Economou, A. Tsiomlektsis, P.D. Tzanavaras, Direct determination of phosphate in urine by sequential-injection analysis with single on-line dilution-calibration method and photometric detection, Anal. Biochem. 330 (2004) 193. 

Five integrated FIA systems have been proposed to measure ethanol extracted from gasohol, and changes were conducted to introduce an on-line dilution process of the... 

Lopez-Gaecia I, SAnchez-Meelos M, Vinas P and HeenAndez-COedoba M (2001) Peristaltic pumps and Fourier transforms inflame atomic absorption spectrometry use of standard additions method and on-line dilution. J Anal Atom Spectrom 16 1185-1189. 

Dynamic range of calibration may be expanded by multistage automated on-line dilutions through sequential injections (zone penetration), zone sampling, etc [15]. 

J.F. van Staden, R.E. Taljaard, On-line dilution with sequential injection analysis a system for monitoring sulphate in industrial effluents, Fresenius J. Anal. Chem. 357 (1997) 577-581. 

In fact, flow analysis presents specific advantages for solving problems related to the sometimes short dynamic concentration ranges in atomie absorption spectrometry, by means of on-line dilution. The eoupling of FI techniques to atomic spectrometric detectors also offers tremendous possibilities to carry out standard additions or internal standardisation. 

Israel, Y., A. Lasztity, and R. M. Barnes. 1989. On-line dilution, steady-state concentrations for inductively coupled plasma spectrometry achieved by tandem injection and merging-stream flow injection. Analyst 114 1259-1265. 

Themelis, D. G., R D. Tzanavaras, and F. S. Kika. 2001. On-line dilution flow injection manifold for the selective spectrophotometric determination of ascorbic acid based on the Fe(II)-2,2 -dipyridyl-2-pyridylhydrazone complex formation. Talanta 55 127-134. 

Wang, J., Hansen, E. H., and Gammelgaard, B. (2001) Flow injection on-line dilution for multi-element determination in human urine with detection by inductively coupled plasma mass spectrometry. Talanta, 55,117-26. 

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