Determination of fungicides in sediments using a dispersive liquid–liquid microextraction procedure based on solidification of floating organic drop

Zhao

et al. 2018

A novel microwave‐assisted‐demulsification dispersive liquid–liquid microextraction technique was established for determination of three triazole fungicides in environmental water samples by gas chromatography with mass spectrometry. Importantly, microwave irradiation has been applied in demulsification to achieve the phase separation and enrichment of triazole fungicides in water samples successfully with low‐density toluene as extractant. The experimental variables, including microwave power, microwave time, ultrasonic time, type and volume of extraction solvent, and effect of salting out were investigated. Under the optimized conditions, the method showed good linearity for myclobutanil, tebuconazole, and difenoconazole in the range of 1–100 μg/L. The limits of detection and the limits of quantification were within the range of 0.14–0.27 and 0.47–0.90 μg/L, respectively. The suitable enrichment factors for three triazole pesticides were in the range of 425–636. The recoveries were between 89.3 and 108.7%, and the relative standard deviations were from 5.4 to 8.6%. Finally, environmental water samples were used to verify the applicability of the proposed method for analysis of triazole fungicides targets. It can be concluded that the developed microwave‐assisted‐demulsification dispersive liquid–liquid microextraction gas chromatography with mass spectrometry method was a rapid, efficient, reliable, and environmental friendly way for analysis of triazole fungicides in water.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microwave‐assisted‐demulsification dispersive liquid–liquid microextraction for the determination of triazole fungicides in water by gas chromatography with mass spectrometry

Zhao

et al. 2018

“…Pretreatment is a very important procedure in OCPs analysis, due to the low abundance of them in environment and the complex matrices. Traditional techniques like LLE and SPE are still widely applied in the analysis of OCPs. The main disadvantages of these methods are their high time consumption and labor intensity, as well as the usage of large quantities of organic solvent.…”

Section: Introductionmentioning

confidence: 99%

Development of ultrasound‐assisted emulsification microextraction based on solidification of a floating organic droplet for determination of organochlorine pesticides in water samples

Bin

Yang

Lee

et al. 2016

An ultrasound-assisted emulsification microextraction based on the solidification of a floating organic droplet followed by gas chromatography with electron capture detection was developed for the simultaneous determination of 13 organochlorine pesticides in water samples. In the proposed method, ultrasound was applied to achieve the emulsification without addition of any dispersive solvent. In consequence, the volume of extraction phase remained unaffected by the ion strength of aqueous phase and high extraction recoveries were obtained. It was also found that dilution of the floating phase with acetone was necessary for preventing peak splitting in chromatogram. Under optimal conditions, the proposed method provided good sensitivity (the detection limits of organochlorine pesticides ranged from 1.3 to 3.9 ng/L) and good repeatability of extraction (below 6.5%, n = 5). The recoveries in reservoir and river water samples were between 75.8% and 96.9%.

“…LPME is the miniaturized implementation of the conventional LLE, in which the amount of organic solvents is greatly reduced. LPME has been performed in different modes, including single drop microextraction (SDME) , headspace LPME , hollow‐fiber (HF) LPME , dispersive liquid–liquid microextraction (DLLME) , and solidified floating organic drop microextraction (SFODME) . LPME has also been the subject of several reviews .…”

Section: Introductionmentioning

confidence: 99%

Simultaneous extraction and quantification of lamotrigine, phenobarbital, and phenytoin in human plasma and urine samples using solidified floating organic drop microextraction and high‐performance liquid chromatography

Asadi

Dadfarnia

Shabani

et al. 2015

A novel and simple method based on solidified floating organic drop microextraction followed by high-performance liquid chromatography with ultraviolet detection has been developed for simultaneous preconcentration and determination of phenobarbital, lamotrigine, and phenytoin in human plasma and urine samples. Factors affecting microextraction efficiency such as the type and volume of the extraction solvent, sample pH, extraction time, stirring rate, extraction temperature, ionic strength, and sample volume were optimized. Under the optimum conditions (i.e. extraction solvent, 1-undecanol (40 μL); sample pH, 8.0; temperature, 25°C; stirring rate, 500 rpm; sample volume, 7 mL; potassium chloride concentration, 5% and extraction time, 50 min), the limits of detection for phenobarbital, lamotrigine, and phenytoin were 1.0, 0.1, and 0.3 μg/L, respectively. Also, the calibration curves for phenobarbital, lamotrigine, and phenytoin were linear in the concentration range of 2.0-300.0, 0.3-200.0, and 1.0-200.0 μg/L, respectively. The relative standard deviations for six replicate extractions and determinations of phenobarbital, lamotrigine, and phenytoin at 50 μg/L level were less than 4.6%. The method was successfully applied to determine phenobarbital, lamotrigine, and phenytoin in plasma and urine samples.