On‐line extraction and determination of two herbicides: Comparison between two modes of three‐phase hollow fiber microextraction

Self Cite

An automated three-phase hollow fiber liquid-phase microextraction based on two immiscible organic solvents followed by high-performance liquid chromatography with UV-Vis detection method was applied for the extraction and determination of exemestane, letrozole, and paclitaxel in water and urine samples. n-Dodecane was selected as the supported liquid membrane and its polarity was justified by trioctylphosphine oxide. Acetonitrile was used as an organic acceptor phase with desirable immiscibility having n-dodecane. All the effective parameters of the microextraction procedure such as type of the organic acceptor phase, the supported liquid membrane composition, extraction time, pH of the donor phase, hollow fiber length, stirring rate, and ionic strength were evaluated and optimized separately by a one variable at-a-time method. Under the optimal conditions, the linear dynamic ranges were 1.8-200 (R = 0.9991), 0.9-200 (R = 0.9987) and 1.2-200 μg/L (R = 0.9983), and the limits of detection were 0.6, 0.3, and 0.4 μg/L for exemestane, letrozole, and paclitaxel, respectively. To evaluate the capability of the proposed method in the analysis of biological samples, three different urinary samples were analyzed under the optimal conditions. The relative recoveries of the three pharmaceuticals were in the range of 91-107.3% for these three analytes.

“…The PFs were obtained from the following equation:

PF = \frac{C_{normala, normalf}}{C_{normald, normali}}

ER % = \frac{n_{normala, normalf}}{n_{normald, normali}} \times 100 = \frac{C_{f, a} V_{f, a}}{C_{d, i} V_{d, i}} \times 100

where n a,f is the number of moles of analyte in the acceptor phase and n d,i is the initial number of moles of analyte in the donor phase .…”

Section: Methodsmentioning

confidence: 99%

“…:

ER % = PF \times (\frac{V_{normala}}{V_{normals}}) \times 100

where V a and V s are the volumes of the acceptor phase and sample solution, respectively. Relative recovery (RR%) was calculated from the following equation:

RR % = \frac{C_{found} - C_{real}}{C_{added}} \times 100

Section: Methodsmentioning

confidence: 99%

Extraction and determination of trace amounts of three anticancer pharmaceuticals in urine by three‐phase hollow fiber liquid‐phase microextraction based on two immiscible organic solvents followed by high‐performance liquid chromatography

Nazaripour

Yamini

Bagheri

2018

Self Cite

“…The conventional LLE and SPE techniques suffer some drawbacks such as time consuming, high cost, and consumption of large volumes of toxic organic solvents and samples. To cope with these problems, microextraction methods such as SPME and LPME have been developed. Although these miniaturize sample pretreatment techniques are rapid, easy, and minimize the use of organic solvents, but suffer from some problems such as sample carryover, fiber fragility, high operational time, and relatively low precisions .…”

Section: Introductionmentioning

confidence: 99%

“…To cope with these problems, microextraction methods such as SPME and LPME have been developed. Although these miniaturize sample pretreatment techniques are rapid, easy, and minimize the use of organic solvents, but suffer from some problems such as sample carryover, fiber fragility, high operational time, and relatively low precisions . To overcome these limitations, dispersive liquid–liquid microextraction (DLLME) was introduced with some advantages including rapidity, low cost, simple operation, and high preconcentration factor .…”

Section: Introductionmentioning

confidence: 99%

Preconcentration of valsartan by dispersive liquid–liquid microextraction based on solidification of floating organic drop and its determination in urine sample: Central composite design

Pebdani

Shabani

Dadfarnia

et al. 2016

In this work, a fast, easy, and efficient dispersive liquid-liquid microextraction method based on solidification of floating organic drop followed by high-performance liquid chromatography with UV detection was developed for the separation/preconcentration and determination of the drug valsartan. Experimental design was applied for the optimization of the effective variables (such as volume of extracting and dispersing solvents, ionic strength, and pH) on the extraction efficiency of valsartan from urine samples. The optimized values were 250.0 μL ethanol, 65.0 μL 1-dodecanol, 4.0% w/v NaCl, pH 3.8, 1.0 min extraction time, and 4.0 min centrifugation at 4000 rpm min(-1) . The linear response (r(2) = 0.997) was obtained in the range of 0.013-10.0 μg mL(-1) with a limit of detection of 4.0 ng mL(-1) and relative standard deviations of less than 5.0 % (n = 6).

“…Recently, membrane‐based microextraction techniques have been used in laboratories and industries for sample preparation . One of the most useful membrane microextraction techniques is hollow‐fiber liquid‐phase microextraction (HF‐LPME) . By applying HF‐LPME, high clean‐up efficiency could be obtained.…”

Section: Introductionmentioning

confidence: 99%

Monosaccharide composition analysis of immunomodulatory polysaccharides by on‐line hollow fiber microextraction with high‐performance liquid chromatography

Wang¹,

Wang²,

Huang³

et al. 2016

The monosaccharide compositions of functional polysaccharides are essential for structure elucidation and biological activity determination. A sensitive method based on on-line hollow-fiber liquid-phase microextraction with high-performance liquid chromatography has been established for the analysis of ten monosaccharide compositions (two uronic acids, two amino sugars and six neutral sugars) of the immunomodulatory polysaccharides. After derivatization, the sample was injected into the lumen of a hollow fiber immersed in butyl ether and separated by liquid chromatography. Under optimized conditions, the calibration curves were linear (r ≥ 0.9996) in the range of 10-2000 μmol L(-1) . The limits of detection were in the range of 0.04-1.58 μmol L(-1) , and the recoveries were in the range of 92.1-99.6%, which shows that the method is applicable to the analysis of the monosaccharide composition of various polysaccharides.