Titrations single-point method

Most uses of flow techniques involve the quantitative determination of some target species. This chapter describes various ways of using flow techniques with quantitative purposes, such as calibration curves, based on peak height or peak area, and titrations, based on distance between equivalence points or single-point method. Stopped-flow technique can be used for both, quantitative approach, for example in kinetic methods, or for qualitative determinations inasmuch as it allows spectral and potential scans to be performed. Multiparameter analysis is presented in two forms to be carried out, by multivariate chemometric techniques or by applying sandwich technique. Finally, smart systems are presented as a step forward in automation, commonly used in multiparameter analysis. 

An interesting method is single-point titration, in which a certain amount of reagent is added to the sample and the ISE potential is measured in the resultant solution [6, 7, 28,62, 64, 66, 77). The authors claim that the precision is similar to that of a classical titration (a relative standard deviation of 0.1 to 1.3%). Time is saved and the method is readily applicable to automated measuring systems. 

At this point I want to emphasize that the procedure I am about to describe bears no relation to the previous titration method, though confusingly similar. The latter is a single-phase titration in octanol, while this is an aqueous-phase titration in the presence of octanol. 

Mg in fertilizers is based on such proceedings thereof has been applied on multiple occasions. In milk fermentation, where the samples were dried, calcined in a furnace at 600 °C, the ash was dissolved in 0.03 M HCl, the solution was centrifuged and the supernatant was thus analyzed . The complexometric method for determination of Ca(II) and Mg(II) can be carried out in a single titration with EDTA in alkaline solution, using a Ca-ISE for potentiometric determination of two endpoints. This is accomplished on digitally plotting pCa values measured by the ISE as a function of the volume V of titrant added to the aliquot of analyte the first and second inflection points of the curve mark the Ca(II) and Mg(n) equivalences, respectively. ... 

The analytical techniques used for single element analysis can be divided into three groups. The first group consists of titration techniques using various means to detect the end point of titration, such as volumetric titration, fluorophotometric titration, potentiometric titration, and spectrophotometric titration. The second group includes direct detection techniques such as direct ternary inclusion compound fluorescent spectrophotometry and the use of ISEs. The third group is that of separation methods such as IC and HPLC, which are used in complicated sample matrices to reduce the sample matrix interference. 

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