Liquid–liquid microextraction without phase separation in a multicommuted flow system for diltiazem determination in pharmaceuticals

Sanchez, Mariana Amorim; Rocha, Fábio R.P.

doi:10.1016/j.aca.2011.03.051

Cited by 12 publications

(10 citation statements)

References 26 publications

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“…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.…”

Section: System Optimizationmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

“…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]. Aiming at biodiesel analysis, liquidliquid microextraction was applied for the determination of iodine value by exploiting reaction of the unsaturated compounds with iodine and the consequent bleaching of a triiodide aqueous solution inserted in between the sample aliquots [21].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Batista

Amais

Rocha

2016

Microchemical Journal

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Section: System Optimizationmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Batista

Amais

Rocha

2016

Microchemical Journal

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“…The binary sampling pattern concept was adopted 28 . Micro-pumps P 1 , P 2 and P 3 , were switched ON/OFF sequentially.…”

Section: Flow System and Proceduresmentioning

confidence: 99%

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

Silva

Souza

Paim

et al. 2018

J. Chil. Chem. Soc.

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A multicommuted flow procedure for the spectrophotometric determination of reducing sugars in wine has been developed. A dialysis unit was incorporated in the system to minimize matrix interferences and eliminate the colored compounds of the wine. The oxidation-reduction reaction in an alkaline medium between reducing sugars and the Cu 2+ -Neocuproine complex was employed. The compound formed was monitored at 460 nm. In the proposed procedure, there was a linear response between 0.25 and 4.0 g L -1 reducing sugars (y = (0.36 ± 0.02) + (0.31 ± 0.01) * x, R = 0.9975, n = 6), a coefficient of variance of 2.6% for a reducing sugar solution of 2.0 g L -1 (n = 7), a limit of detection estimated at 0.03 g L -1 , reagent consumption per determination of 0.330, 0.128 and 0.160 mg for neocuproine, CuSO 4 and NaOH, respectively. A sampling throughput of 45 determinations per hour was achieved. The proposed system was applied to wine samples and comparing the results with an AOAC official method no significant difference at a 95% confidence level.

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“…PRA has been determined by capillary electrophoretic method [9], liquid chromatography [10], gas chromatography employing chemical ionization mass spectrometry (GC/CIMS) [11], HPTLC [12] and enzyme immunoassay [13]. Reported methods for the determination of DTZ and its metabolites include spectrophotometry [14], amperometry [15], HPLC [16], HPTLC [17], capillary gas chromatography [18] and liquid-liquid micro-extraction [19]. Different techniques have been reported for the determination of NAP i.e.…”

Section: Introductionmentioning

confidence: 99%

An Ultra-Sensitive and Selective LC-UV Method for the Simultaneous Determination of Pravastatin, Diltiazem, Naproxen Sodium and Meloxicam in API, Pharmaceutical Formulations and Human Serum

Sultana¹

2013

AJAC

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Abstract:The aim of the present work was to develop a sensitive liquid chromatographic method for the quantitation of pravastatin and diltiazem along with naproxen and meloxicam using ultraviolet detector. The separation of components was achieved on Purospher Star, C 18 (5 µm, 25 x 0.46 cm) column using methanol-water (80:20 v/v) as mobile phase and pH adjusted 3.4 with 85% o-phosphoric acid. Related parameters that may influence the enrichment efficiency of speration of drugs such as the kind and volume of elute, sample flow rate, sample pH, and volume of the drug samples were investigated. Detection was performed at ambient temperature at 220 nm by pumping the mobile phase at the flow rate 1.0 mL min -1 . The experimental results indicated a good linearity (R 2 > 0.9947) over the concentration range of 0.5-20 µg mL -1 for pravastatin, naproxen and meloxicam and 0.75-24 µg mL -1 for diltiazem. The method was compared by programming the detector adjusting the wavelength with time to match the individual analyte's chromophore which enhanced sensitivity with linear range 0.25-8.0, 0.5-16, 0.4-12 and 0.2-4.0 µg mL -1 for pravastatin, diltiazem, naproxen and meloxicam respectively. The LOD values shifted down from 33, 70, 50 and 80 ng mL -1 to 15, 42, 20 and 10 ng mL -1 for pravastatin, diltiazem, naproxen and meloxicam respectively. Validation of the method showed good precision and accuracy for the proposed method. All the results indicated that this procedure could allow the simultaneous determination of these four compounds in API, pharmaceutical formulations and serum at trace levels. The method can be successfully applied for the determination of these drugs in human serum, clinical laboratories and in pharmaceutical formulations without diode array detector and without interference of excipients or endogenous components of serum.

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Liquid–liquid microextraction without phase separation in a multicommuted flow system for diltiazem determination in pharmaceuticals

Cited by 12 publications

References 26 publications

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

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

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

An Ultra-Sensitive and Selective LC-UV Method for the Simultaneous Determination of Pravastatin, Diltiazem, Naproxen Sodium and Meloxicam in API, Pharmaceutical Formulations and Human Serum

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