A multicommuted flow system with liquid–liquid microextraction for determination of anionic surfactants in freshwaters

Submicrometric Magnetic Nanoporous Carbons Derived from Metal–Organic Frameworks Enabling Automated Electromagnet-Assisted Online Solid-Phase Extraction

“…The obtained detection limits are comparable with those obtained using other reported procedures for the determination of SDS. [40][41][42][43] Furthermore, the proposed method just requires of 150 µL methanol as eluent, so using an organic solvent which is less toxic than the CHCl 3 used in the reference method and requiring an organic solvent volume per analysis approximately 300-fold lower. 38 The organic solvent volume used in the developed method is also much smaller than the required in other reported batch procedures (80 and 30-fold less volume, respectively), 44,45 Furthermore, in front of the 1.5 ml of sample used in the developed procedure, the official standard method requires up to 400 mL of sample to achieve similar levels of sensitivity, which makes more difficult the handling and storage of a large number of samples.…”

Liquid–liquid microextraction in sequential injection analysis for the direct spectrophotometric determination of acid number in biodiesel

“…As this process refers to the interface sample/indicator, the effect of the sample volume is limited by the time available for diffusion of FFA to the interface and then the residence time. According to previous studies that exploited a similar approach, the volume of the second sample aliquot presented less influence in the extraction as its main function is to constrain dispersion of the extractor zone [19][20][21]. However, these procedures were performed by flow injection analysis, which employ unidirectional flow.…”

“…However, flow injection liquid-liquid microextraction is a feasible strategy that has been demonstrated in the literature [19][20][21]. Microextraction is based on the non-exhaustive analyte transference from large amounts of sample to micro portions of an acceptor phase [19,22].…”

Spectrophotometric Determination of Reducing Sugar in Wines Employing in-Line Dialysis and a Multicommuted Flow Analysis Approach

“…These methodologies have been well reported, such as automation tools for handling solutions and pre-treatment of samples 7 . Examples include the coupling of interfaces in flow analysis for pre-treatment of sample such as, gas-liquid (gas diffusion, distillation and hydride generation), liquid-liquid (extraction and dialysis) and liquid-solid (ion exchange, adsorption, precipitation, dissolution and stripping) [8][9][10][11][12][13][14] . The indirect determination of RS in of wine employing the classical Fehling's reaction and flow injection coupled to atomic absorption spectrometry (AAS) was reported by Yebra et al (1993) 15 .…”

“…Other approach uses of the MCFIA have been with micro-pumps, devices that produce a pulsed flow, thus increasing the interactions between the solutions in the MCFIA system 6 . Furthermore, environmentally friendly systems and highly sensitive analyses have been achieved 9,12,22 . Additional advantages of the micro-pumps in a multicommutation system include portability, low energy requirements and the ability to minimize volume reagent consumed and consequently waste generation 23,24 .…”