Multidetection in unsegmented flow systems with a single detector

Kinetic‐based determinations in continuous‐flow analysis

“…The time difference between the arrival of both reacting plugs to the detector is fixed by the coil situated between the valves [6]. (c) A closed system in which, after injection by means of a valve placed outside or within the closed circuit, the sample is continuously circulated through the closed loop until complete homogenization with the enclosed carrier is achieved; a series of signals are b) obtained whose envelope, in the shape of a typical kinetic curve, provides interesting kinetic information on the system, in addition to the data related to the analyte concentration [7][8][9][10]. (d) The three most interesting possibilities of this type are: (1) splitting the injected sample into two subplugs which pass through the reactor to the cells; the subplugs are aligned with the optical path of a single detector (this is used for speciation of chromium in waters [11]).…”

A Multicommutated Flow System Based on an Opened‐Loop with Micropump Propulsion

“…Nevertheless, with slight differences in the closed-loop configuration, those flow systems were employed in other analytical purposes, like multiple-peak recording of one injected sample with only one detector (Ríos et al 1985;Valcárcel et al 1989), regeneration of reagents (Ríos et al 1987), determination of conventional kinetics parameters (Ríos et al 1985), simultaneous determination of species by kinetics methods (Ríos et al 1986), solvent extraction (sample preconcentration) (Atallah et al 1987), sample dilutions (Ríos et al 1985), and amplification of the determination range (Valcárcel et al 1989).…”

Automatic flow system for simultaneous determination of iron and chromium in steel alloys employing photometers based on LEDs as radiation source

“…When analytes compound absorb radiation at the same wavelengths, the flow networks have been designed to determine each analyte at a different time [5]. On the other hand, if chemical species absorb at a different wavelength, simultaneous determination had been carried out, nevertheless equipment with the ability to sweep automatically the wavelengths have been employed [6,7].…”

“…When analytes compound absorb radiation at the same wavelengths, the flow networks have been designed to determine each analyte at a different time [5]. On the other hand, if chemical species absorb at a different wavelength, simultaneous determination had been carried out, nevertheless equipment with the ability to sweep automatically the wavelengths have been employed [6,7].A light-emitting diode (LED) has been employed as a radiation source in some photometric procedures, its advantages being robustness and low current consumption [8,9]. Nevertheless, depending on the LED type, the width of the emission band can range from 30 to 100 nm [10][11][12][13].…”