Dispersive Liquid-Liquid Microextraction Method for the Simultaneous Determination of Four Isomers of Hexachlorocyclohex
- PDF / 1,688,500 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 98 Downloads / 215 Views
Dispersive Liquid-Liquid Microextraction Method for the Simultaneous Determination of Four Isomers of Hexachlorocyclohexane and Six Pyrethroid Pesticides in Milk by Gas Chromatography Electron Capture Detector Yuanling Zhao 1 & Xi’ai Hou 1 & Dongmei Qin 2 & Dan Liu 1 Received: 28 June 2019 / Accepted: 14 October 2019 # Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract In this study, a simple and rapid dispersive liquid-liquid microextraction method was established, and the residuals of four isomers of hexachlorocyclohexane and six kinds of pyrethroid pesticides in milk were simultaneously determined by gas chromatography electron capture detector (GC-ECD). The milk sample was first extracted with acetonitrile and cleaned with primary secondary amine (PSA). Then 0.5 mL of acetonitrile was mixed with 140 μL of cyclohexane and rapidly injected into 3 mL of pure water. After vortexing and centrifugation, the floating phase was removed with a 0.1-mL pipette into the GC-ECD. The type and volume of extraction solvent, volume of disperser solvent, volume of water, vortex time, and amount of salt were optimized. Under optimal extraction conditions, the ten pesticides showed a good linear relationship in a certain concentration range in milk matrix, and the correlation coefficients were greater than 0.99. The limits of detection ranged from 0.07 to 2 μg/kg, and the limits of quantitation ranged from 0.2 to 5 μg/kg. The average recovery rates were between 70.1% and 106.3%, and the relative standard deviations were less than 15.2%. This method can be used for the determination of hexachlorocyclohexane and pyrethroid pesticides in milk and for subsequent research. Keywords Dispersive liquid-liquid microextraction . Floating organic drop . Milk . Hexachlorocyclohexane and pyrethroid pesticides
Introduction Milk is very important in the human diet and contains nutrients, such as proteins, that are necessary for human health. Because some pesticides are distributed in crops and even contaminate soil and water, these compounds are enriched in the food chain and are therefore present in milk (Dagnac et al. 2009). Hexachlorocyclohexane was widely applied in the world in the 1960s and 1970s. The use of this pesticide stopped in the 1980s due to its high toxicity, long persistence, difficult decomposition, wide distribution, heavy damage, and difficulty * Dan Liu [email protected] 1
Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100194, People’s Republic of China
2
Institute Control of Agrochemicals, Ministry of Agriculture, Beijing 100125, People’s Republic of China
of remediation in the environment (Singh and Nelapati 2017). Lindane is still used in a few areas (Berger et al., 2016). After cows ingest feed, forage, water, and soil contaminated with pesticides, these pesticides are converted and accumulate in the cows, so some harmful pesticide residues are detected in the milk (Salas et al. 2003). The maximum residue limit for lindane in milk, as prescribed by
Data Loading...
