Optimization of a phase separation based magnetic-stirring salt-induced liquid–liquid microextraction method for determination of fluoroquinolones in food

Gao, Ming; Wang, Huili; Ma, Meiping; Zhang, Yuna; Yin, Xiaobin; Dahlgren, Randy A.; Du, Dongli; Wang, Xuedong

doi:10.1016/j.foodchem.2014.11.132

Cited by 44 publications

(11 citation statements)

References 44 publications

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“…This method enhances the signal-to-noise ratio of flow detection. 32 The decorrelation signal, representing here the blood flow signal for OCTA, is a function of light scattering due to the displacement of red blood cells over time. The subspectra used in SSADA have one quarter of the full OCT bandwidth and support an angiographic depth resolution of 20 μm, which is sufficient to resolve the retinal plexuses.…”

Section: Methodsmentioning

confidence: 99%

OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia

Hagag

Pechauer

Liu

et al. 2018

Ophthalmology Retina

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Purpose Use projection-resolved OCT angiography to investigate the autoregulatory response in the 3 parafoveal retinal plexuses under hyperoxia. Design Prospective cohort study. Participants Nine eyes from 9 healthy participants. Methods One eye from each participant was scanned using a commercial spectral-domain OCT system. Two repeated macular scans (3 × 3 mm2) were acquired at baseline and during oxygen breathing. The split-spectrum amplitude-decorrelation algorithm was used to detect blood flow. The projection-resolved algorithm was used to suppress projection artifacts and resolve blood flow in 3 distinct parafoveal plexuses. The Wilcoxon signed-rank test was used to compare baseline and hyperoxic parameters. The coefficient of variation, intraclass correlation coefficient, and pooled standard deviation were used to assess the reliability of OCT angiography measurements. Main Outcome Measures Flow index and vessel density were calculated from the en face angiograms of each of the 3 plexuses, as well as from the all-plexus inner retinal slab. Results Hyperoxia induced significant reduction in the flow index (−11%) and vessel density (−7.8%) of only the deep capillary plexus (P < 0.001) and in the flow index of the all-plexus slab (P = 0.015). The flow index also decreased in the intermediate capillary plexus and the superficial vascular complex, but these changes were small and not statistically significant. The projection-resolved OCT angiography showed good within-session baseline repeatability (coefficient of variation, 0.8%–5.2%; intraclass correlation coefficient, 0.93–0.98) in all parameters. Relatively large between-day response reproducibility was observed (pooled standard deviation, 1.7%–9.4%). Conclusions Projection-resolved OCT angiography was able to show that the retinal autoregulatory response to hyperoxia affects only the deep capillary plexus, but not the intermediate capillary plexus or superficial vascular complex.

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Section: Methodsmentioning

confidence: 99%

OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia

Hagag

Pechauer

Liu

et al. 2018

Ophthalmology Retina

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“…The PS‐MSSI‐HT‐LLE was applied after significant adaptation to the procedure previously published by Wao and coauthors regarding the determination of five FQs using high‐performance liquid chromatography . Alongside to adaptations of this reported sample preparation, it is proposed here a compact BIA‐AD system.…”

Section: Resultsmentioning

confidence: 99%

“…To demonstrate the potentialities of this approach, the emerging contaminant levofloxacin was quantified in tap, river and aquarium water samples. This procedure is an adaptation of previously published work that detected FQs in complex animal‐based samples (milk, egg and honey) by HPLC . Here, a more compact method, which uses stirring hot plates, allows the control of temperature and agitation in an isolated device.…”

Section: Introductionmentioning

confidence: 99%

Liquid‐liquid Extraction Coupled to Batch Injection Analysis for Electroanalysis of Levofloxacin at Low Concentration Level

et al. 2017

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This work presents the integration between phase‐separation by magnetic‐stirring salt‐induced high‐temperature liquid‐liquid extraction (PS‐MSSI‐HT‐LLE) and batch injection analysis with amperometric detection (BIA‐AD) as an alternative strategy for pre‐concentration of analytes before hydrodynamic electroanalysis. To demonstrate the performance of this analytical system, the emerging contaminant levofloxacin was quantified in tap, aquarium and lake water at low concentration level. In the optimized conditions, BIA‐AD enabled fast (160 h−1) and reproducible results (RSD<2 %) and the PS‐MSSI‐HT‐LLE allowed the detection of levofloxacin concentration levels not detected by direct electroanalysis (70 and 80 nmol L−1) corresponding to 100‐folds enrichment factors. The performance of proposed method was evaluated by addition‐recovery test and was obtained satisfactory recovery values (between 70 and 96 %). Moreover, PS‐MSSI‐HT‐LLE allows the pre‐concentration of many samples simultaneously, which is advantageous over pre‐concentration on working electrode surface (stripping methods).

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“…Fluoroquinolones are among the most important antibacterial agents which were developed in the 80s and are now widely used in medicine and veterinary medicine [49]. erefore, several analytical procedure has been reported for determination of fluoroquinolones including high-performance liquid chromatography (HPLC) [50][51][52][53][54][55][56][57][58][59][60][61][62], spectrophotometry [63], fluorimetry [64][65][66][67][68][69][70][71][72][73], flow-injection based on chemiluminescence [74][75][76], chemiluminescence [77,78], terbium-sensitized luminescence [79], solid-phase spectrofluorimetry [80,81], capillary electrophoresis [82,83], convenient magnetic solid-phase extraction procedure coupled with capillary electrophoresis [84], solid-phase microextraction coupled with liquid chromatography-tandem mass spectrometry [85], liquid-liquid microextraction [86], polarography [87], and colorimetry [88] But, there is no report for application of PAT or PAC for online monitoring of fluoroquinolones.…”

Section: Introductionmentioning

confidence: 99%

Fiberoptic-Coupled Spectrofluorometer with Array Detection as a Process Analytical Chemistry Tool for Continuous Flow Monitoring of Fluoroquinolone Antibiotics

Shokoufi

Vosough

Rahimzadegan-Asl

et al. 2020

International Journal of Analytical Chemistry

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Nowadays, there is an increasing need for sensitive real-time measurements of various analytes and monitoring of industrial products and environmental processes. Herein, we describe a fluorescence spectrometer in continuous flow mode in which the sample is fed to the flow cell using a peristaltic pump. The excitation beam is introduced to the sample chamber by an optical fiber. The fluorescence emitted upon excitation is collected at the right angle using another optical fiber and then transmitted to the fluorescence spectrometer which utilizes an array detector. The array detection, as a key factor in process analytical chemistry, made the fluorescence spectrometer suited for multiwavelength detection of the fluorescence spectrum of the analytes. After optimization of the experimental parameters, the system has been successfully employed for sensitive determination of four fluoroquinolone antibiotics such as ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin. The linear dynamic ranges of four fluoroquinolones were between 0.25 and 20 μg·mL−1, and the detection limit of the method for ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin were 81, 36, 35, and 93 ng·mL−1, respectively. Finally, the proposed system is carried out for determination of fluoroquinolones in some pharmaceutical formulations.

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Optimization of a phase separation based magnetic-stirring salt-induced liquid–liquid microextraction method for determination of fluoroquinolones in food

Cited by 44 publications

References 44 publications

OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia

OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia

Liquid‐liquid Extraction Coupled to Batch Injection Analysis for Electroanalysis of Levofloxacin at Low Concentration Level

Fiberoptic-Coupled Spectrofluorometer with Array Detection as a Process Analytical Chemistry Tool for Continuous Flow Monitoring of Fluoroquinolone Antibiotics

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