Optimization of dispersive liquid-liquid microextraction with central composite design for preconcentration of chlordiazepoxide drug and its determination by HPLC-UV

Abstract

A simple, rapid, and sensitive method based on dispersive liquid-liquid microextraction combined with HPLC-UV detection applied for the quantification of chlordiazepoxide in some real samples. The effect of different extraction conditions on the extraction efficiency of the chlordiazepoxide drug was investigated and optimized using central composite design as a conventional efficient tool. Optimum extraction condition values of variables were set as 210 μL chloroform, 1.8 mL methanol, 1.0 min extraction time, 5.0 min centrifugation at 5000 rpm min(-1), neutral pH, 7.0% w/v NaCl. The separation was reached in less than 8.0 min using a C18 column using isocratic binary mobile phase (acetonitrile/water (60:40, v/v)) with flow rate of 1.0 mL min(-1) The linear response (r(2) > 0.998) was achieved in the range of 0.005-10 μg mL(-1) with detection limit 0.0005 μg mL(-1) The applicability of this method for simultaneous extraction and determination of chlordiazepoxide in four different matrices (water, urine, plasma, and chlordiazepoxide tablet) were investigated using standard addition method. Average recoveries at two spiking levels were over the range of 91.3-102.5% with RSD < 5.0% (n = 3). The obtained results show that dispersive liquid-liquid microextraction combined with HPLC-UV is a fast and simple method for the determination of chlordiazepoxide in real samples.

Comparison of air‐agitated liquid–liquid microextraction and ultrasound‐assisted emulsification microextraction for polycyclic aromatic hydrocarbons determination in hookah water

“…To study the effect of the extracting solvent volume, different volumes of carbon tetrachloride (15,20,25, and 30 L) were used using the same extraction procedure. The results obtained showed that by increasing the volume of carbon tetrachloride from 15 to 30 L, the analytical signals decreased rapidly.…”

“…In 2006, a rapid, simple, and low‐cost LPME method with a high enrichment factor, namely, dispersive LLME, was proposed . It immediately gained considerable attention from researchers . However, it is based upon a ternary component solvent system, in which utilization of the cosolvents (disperser solvents) leads to some disadvantages such as decrease in the partition coefficients for extraction of the analytes into the extracting solvent and increase in the cost and environmental pollution.…”

Preparation of Pyridine N-oxide Derivatives in Microreactor

“…The N-oxide type molecules can be found in several active pharmaceutical ingredients (such as: Chlordiazepoxide as sedative, [2] Tirapazamine as anticancer, [3] Phenazopyridine, [4] Flupirtine, [5] Propirame [6] as analgestic, Phenyramidol muscle relaxant [7]) (Figure 1), in addition N-oxides are typical metabolic intermediates in the human organism, so the synthetic preparation of those N-oxides from tertiary amines has a high importance in drug development [8].…”

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

“…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 . Despite the many benefits of DLLME, the choice of the extraction solvent is still a drawback.…”