Mixed surfactant systems based on primary amine and medium-chain fatty acid: Micelle-mediated microextraction of pesticides followed by the GC–MS determination
Graphical abstract
Introduction
The use of pesticides in modern agriculture is the most widespread way to protect plants from pests due to the rapid application over the large areas, high efficiency and low cost considering its low working concentrations. Despite these advantages, pesticides can cause the negative impact on the environment such as phytotoxicity and massive death of beneficial insects and animals. Excessive use of these substances leads to serious human health disorders including allergic reactions, cancer tumors, birth defects and neurological damage [1]. Therefore, concentrations of pesticides in edible plants and plant-based food have to be under control to prevent above-mentioned undesirable effects on humans and environment.
High-performance liquid chromatography (HPLC), gas chromatography (GC) or capillary electrophoresis combined with mass-spectrometry (MS) as well as immunoassay are the most frequently used analytical methods for the determination of different pesticides in various samples [2]. It should be noted, that various electrochemical, optical and piezoelectric sensors are also used for this analytical challenge, but their sensitivity and life-time are often limited [3].
Taking into account the complexity of food sample matrices the pretreatment of samples is required. It helps to eliminate matrix interference and increase sensitivity by pre-concentration. Various liquid-liquid extraction (LLE), solid-phase extraction (SPE) and well-known QuEChERS techniques are usually applied for the extraction and pre-concentration of pesticides [4]. Conventional LLE and SPE techniques are usually tedious, time-consuming and require large volumes of toxic organic solvents.
Micelle-mediated microextraction can be considered as an environmentally friendly and inexpensive alternative to the existing methods. It is based on the ability of surfactant molecules at sufficient concentration to form micelles in aqueous solution, which can extract hydrophobic compounds. Surfactant-rich phase can be separated by changing temperature, ionic strength or pH, with subsequent determination of the analytes in the extract. Various surfactant (non-ionic [[5], [6], [7]], anionic [8], cationic [9] and mixed [10]) systems have been reported for the preconcentration of pesticides from environmental, food and biological samples (Table 1). One of the limitations of the procedures proposed is high viscosity of the surfactant-rich phase, which is unacceptable for direct injection into a liquid or gas chromatography equipment. Usually in order to reduce viscosity of the surfactant-rich phase its dilution [[8], [9], [10], [11], [12], [13], [14]], precipitation [6] or re-extraction [5,15] is implemented. Such procedures can reduce sensitivity due to dilution effect and require additional reagents and solvents and can be time-consuming. The search for new effective surfactant systems has interest in sample pretreatment based on the micelle-mediated microextraction.
In this work, it was found that mixed surfactant systems based on primary amine and medium-chain fatty acid promote formation of non-viscous surfactant-rich phases caused by changes in the ionic strength. To the best of our knowledge, the application of such systems for micelle-mediated microextraction has not been presented in literature. In this research, the surfactant-rich phases obtained after phases separation were withdrawn into a conventional chromatographic syringe and injected directly into a gas chromatography–mass spectrometry (GC–MS) system without any dilution to reduce phase viscosity. A novel approach was implemented for the micelle-mediated microextraction of pesticides (diazinon, triadimefon, triadimenol and bifenthrin, Fig. 1) from food samples followed by the GC–MS determination. Studied analytes are widely used in agriculture in different countries including Russia and their concentrations are strictly regulated in foods [16,17].
Section snippets
Reagents and solutions
All chemicals were of analytical reagent grade. All pesticides (diazinon (99.0%), triadimefon (99.5%), triadimenol (99.5%) and bifenthrin (98.0%)) were purchased from Ecolan (Moscow, Russia). Stock solutions of analytes (1 g L−1 of each pesticide) were prepared by dissolving an appropriate amount of each pesticide in methanol and stored in a refrigerator at 4 °C. Methanol (≥99.8%) was purchased from J.T. Baker Chemical Company (Phillipsburg, NJ, USA). Working solutions and mixtures of the
Preliminary studies
In this study several primary amines (1-butyl-, 1-pentyl-, 1-hexyl-, 1-heptyl-, 1-octyl-, 1-nonyl- and 1-decylamine) and fatty acids (pivalic, hexanoic, octanoic and nonanoic acids) in different ratios were studied as precursors of mixed surfactant systems for micelle-mediated microextraction of pesticides. The experimental investigations were provided as follows: 1 mL of pesticides solution was mixed with 50 μL of primary amine, fatty acid or extraction mixture containing primary amine and
Conclusions
Mixed surfactant systems based on primary amines (1-butyl-, 1-pentyl-, 1-hexyl-, 1-heptyl-, 1-octyl-, 1-nonyl- and 1-decylamine) and medium-chain fatty acids (pivalic, hexanoic, octanoic and nonanoic acid) were investigated for the micelle-mediated microextraction. It was found that the mixed surfactant system based on 1-nonylamine and pivalic acid (3:2, v/v) provided formation of surfactant-rich phase and maximum extraction of pesticides from aqueous phase. The surfactant-rich phase was
CRediT authorship contribution statement
Daria Kanashina: Methodology, Formal analysis, Writing - original draft, Visualization. Aleksei Pochivalov: Methodology, Writing - original draft, Visualization. Irina Timofeeva: Conceptualization, Methodology, Writing - original draft, Writing - review & editing, Funding acquisition. Andrey Bulatov: Supervision, Writing - original draft, Writing - review & editing.
Acknowledgements
The study reported was funded by the Russian Science Foundation (project no. 19-73-00121). Scientific research was performed using the equipment of the Chemistry Educational Centre and the Center for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics of the Research Park of Saint Petersburg State University, Russia.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (24)
- et al.
Pesticides human health effects
- et al.
Progress of the discovery, application, and control technologies of chemical pesticides in China
J. Integr. Agric.
(2019) - et al.
Review of optical sensors for pesticides
TrAC Trends Anal. Chem.
(2018) - et al.
A review of extraction, analytical and advanced methods for determination of pesticides in environment and foodstuffs
Trends Food Sci. Technol.
(2018) - et al.
Cloud point extraction coupled with ultrasonic-assisted back-extraction for the determination of organophosphorus pesticides in concentrated fruit juice by gas chromatography with flame photometric detection
Food Chem.
(2011) - et al.
Determination of prometryne in water and soil by HPLC–UV using cloud-point extraction
Talanta
(2009) - et al.
Micellar extraction of organophosphorus pesticides and their determination by liquid chromatography
Anal. Chim. Acta
(2004) - et al.
Acid-induced cloud-point extraction coupled to spectrophotometry for the determination of carbaryl residues in waters and vegetables
Microchem. J.
(2008) - et al.
Cloud point extraction for determination of Diazinon: optimization of the effective parameters using Taguchi method
Chemom. Intell. Lab. Syst.
(2012) - et al.
Determination of triazine herbicides in milk by cloud point extraction and high-performance liquid chromatography
Food Chem.
(2014)
Cloud point extraction and determination of trace trichlorfon by high performance liquid chromatography with ultraviolet-detection based on its catalytic effect on benzidine oxidizing
Anal. Chim. Acta
Determination of triazole fungicides in environmental water samples by high performance liquid chromatography with cloud point extraction using polyethylene glycol 600 monooleate
Anal. Chim. Acta
Cited by (8)
Surfactants application in sample preparation techniques: Insights, trends, and perspectives
2023, TrAC - Trends in Analytical ChemistryInnovative approaches in cloud-point extraction
2023, Journal of Chromatography APlant sterol precipitation in system composed by fatty acids using in-situ synthesized ionic liquids
2023, Chemical Engineering JournalProtic ionic liquids based on fatty acids: A mixture of ionic and non-ionic molecules
2023, Journal of Molecular Liquids