Incorporation of flow injection analysis with dual-wavelength overlapping resonance Rayleigh scattering for rapid determination of malachite green and its metabolite in fish

Micro flow injection analysis of leucomalachite green in fish muscle using modified henequen fibers as microfluidic channels

In this work a simple and novel procedure for leucomalachite green determination based on micro flow injection analysis (μFIA) with amperometric detection is presented. The method involves the use of henequen modified fibers as microfluidic channels. The μFIA system proposed offers a simple, rapid, and low-cost alternative for the determination. Capillary and gravitational forces across the modified henequen fibers control the flow rate, eliminating the need for external pumps. This technique requires low reagent consumption and allows portability for in situ measurements. The flow system is described, and the operational variables were studied and optimized using a Taguchi parameters design to increase analytical sensitivity. Under optimal conditions a limit of detection of 1.16 μg kg⁻¹ was achieved with adequate repeatability and reproducibility (expressed as %RSD <5.0%, n = 3, n = 9 respectively) in all cases. The effect of interfering species and the accuracy of the method were also investigated. The proposed methodology was validated and applied to determine LMG in tilapia muscle samples.

In this work a simple and novel procedure for leucomalachite green determination based on micro flow injection analysis (μFIA) with amperometric detection is presented.

Study on Brilliant Blue-chitosan System by Dual-wavelength Overlapping Resonance Rayleigh Scattering Method and its Analytical Applications

The method was presented for the sensitive and selective determination of chitosan (CTS) in health products with Brilliant Blue (BB) as a probe, based on dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS). In weakly acidic buffer solution, the binding of CTS and BB could result in the RRS intensities getting enhanced significantly at RRS peaks of 344nm and 452nm, and the scattering intensities of the two peaks were proportional to the concentration of CTS within a certain range. When the RRS intensities of the two wavelengths were superposed, the results showed higher sensitivity. Under the optimum experimental conditions, the total of the two increased RRS intensities was linear to the CTS concentration in the range of 0.02-1.80μg/mL and the limit of detection (LOD) was 7.45ng/mL. In this work, the optimum conditions and the effects of some foreign substances were studied. Accordingly, the new method based on DWO-RRS for the determination of CTS was developed. In addition, the effect of the molecular weight and the deacetylation degree between different chitosan molecules was discussed. Finally, this assay was applied to determine the concentration of CTS in health products with satisfactory results.

Recent advances in flow injection analysis

A dynamic development of methodologies of analytical flow injection measurements during four decades since their invention has reinforced the solid position of flow analysis in the arsenal of techniques and instrumentation of contemporary chemical analysis.

Triple-wavelength overlapping resonance Rayleigh scattering method for facile and rapid assay of perfluorooctane sulfonate

In the present study, a novel triple-wavelength overlapping resonance Rayleigh scattering (TWO-RRS) method had been well established to detect perfluorooctane sulfonate (PFOS). We found that crystal violet (CV) could react with PFOS to form 1:1 ion-association complex by electrostatic attraction and hydrophobic effect over a wide pH range (5.0∼11.0) in less than 60 s. The complexes would further self-aggregated into nanoparticles [CV-PFOS]n. Based on this phenomenon, not only the absorption and Raman spectra were changed but also the resonance Rayleigh scattering (RRS) intensities were significantly enhanced. And three new RRS peaks located at 327, 492, and 654 nm were clearly observed, respectively. At the same time, it was found that both the enhanced single-wavelength resonance Rayleigh scattering (SW-RRS) and TWO-RRS intensities against the concentration of PFOS showed an excellent correlation. The detection limits for the three single peaks were 27.4 nmol L(-1) (13.7 μg L(-1), 327 nm), 27.5 nmol L(-1) (13.8 μg L(-1), 492 nm), and 31.4 nmol L(-1) (15.7 μg L(-1), 654 nm), and for TWO-RRS method was 5.9 nmol L(-1) (3.0 μg L(-1)). Moreover, it could be applied to determine PFOS water samples successfully.

A novel method for detecting allura red based on triple-wavelength overlapping resonance Rayleigh scattering

A simple, sensitive and selective assay was established to detect trace allura red with ethyl violet in drinks, based on triple-wavelength overlapping resonance Rayleigh scattering.