Rapid analysis of pesticide residues in drinking water samples by dispersive solid-phase extraction based on multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry

Effect of resolution enhancement using metal ion assisted strategy based on electrospray ionization-ion mobility spectrometry: A case study of carbendazim and thiabendazole in fruits

A method for the rapid and simultaneous determination of carbendazim and thiabendazole residues by electrospray ionization-ion mobility spectrometry (ESI-IMS) combined with a metal ion-assisted technique was developed and validated in different fruit matrices. The metal ion assisted strategy was performed instead of tedious pre-separation procedures to overcome the limitation of low resolution of IMS. Four transition metal cations, Co(II), Ni(II), Cu(II), and Zn(II), were screened and their interactions with carbendazim and thiabendazole were investigated. The injection flow rate and metal ion concentration were optimized. The Cu(II) assisted approach helped to achieve well-separated peaks with a peak-to-peak resolution of 3.61. This method was then applied to detect carbendazim and thiabendazole simultaneously in apples, pears, bananas, and mangoes. The limit of detection (LOD) were 0.03 mg kg-1 and 0.13 mg kg-1 for carbendazim and thiabendazole, respectively, while spiked recoveries were 61.5-122.0% and 83.5-119.8%, respectively, with RSDs less than 13.9%. These satisfactory evaluation parameters indicated that the approach was capable of performing quantitative analysis of multi-pesticide residues. In addition, the feasibility of using metal ion assisted-ESI-IMS for the simultaneous detection also was theoretically demonstrated through molecular electrostatic potential analysis and binding energy calculation based on density functional theory (DFT). Both experimental and theoretical results revealed the effectiveness of the metal ion assisted strategy in improving the resolution of ESI-IMS.

Polycarbonate-coated magnetic nanoparticles for the extraction of imipramine and its primary metabolite from urine

This study introduces a reliable and inexpensive magnetic dispersive solid phase extraction to extract imipramine and its primary metabolite (desipramine) from urine samples. To accomplish this aim, Fe3 O4 magnetic nanoparticles were synthesized by sonication, subsequently, polycarbonate was precipitated gradually onto the surface of them to form the adsorbent. Extraction recoveries of 85% and 76%, enrichment factors of 57 and 51, limits of detection of 2.5 and 2.8 μg/L, and limits of quantification of 8.3 and 9.3 μg/L were obtained for imipramine and desipramine under the optimal conditions, respectively. In addition, relative standard deviations for intra- (n = 6) and inter-day (n = 5) precisions at two concentrations (50 and 100 μg/L of each analyte) were less than or equal to 4%. Short extraction time, good repeatability, high enrichment factors, and simplicity are the main advantages of the proposed method.

Reusable passive sampler with carbon nanotubes for monitoring contaminants in wastewater: Application, regeneration and reuse

Progress in excogitation suitable strategies for monitoring chemical compounds in wastewater is an essential step for further research into the occurrence, impact, and fate of the pollutants in the aquatic environment. At present, it is desirable to advance and use economical, environmentally friendly and non-labour intensive methods of environmental analysis. In this study, carbon nanotubes (CNTs) were successfully applied, regenerated, and reused as a sorbent in passive samplers for monitoring contaminants in treated and untreated wastewater at three wastewater treatment plants (WWTPs) located in different urbanization areas in northern Poland. Three cycles of chemical and thermal regeneration of used sorbents were performed. It was shown that it is possible to regenerate CNTs a minimum of three times and reuse them in passive samplers while maintaining the desired sorption properties. The obtained results confirm that the CNTs are perfectly in line with the main principles of green chemistry and sustainability. Carbamazepine, ketoprofen, naproxen, diclofenac, p-nitrophenol, atenolol, acebutolol, metoprolol, sulfapyridine and sulfamethoxazole were detected in each of the WWTPs, both in treated and untreated wastewater. The obtained data drastically show the inefficiency of the removal of contaminants by conventional WWTPs. More importantly, the results even indicate negative contaminant removal in most cases, i.e. higher concentrations (up to 863%) of these substances in the effluent compared to the influent.

Dynamic light scattering and zeta-potential as a tool for understanding the mechanism of pesticides binding toward individual components of transition metal nanoparticles and graphene oxide hybrids

Pesticides present in their commercial formulations are studied for their preferable binding toward carbon-based graphene oxide (GO) or transition metal nanoparticles (Fe, Co, Ni, and Cu), present as hybrids. This simple study also reveals the mechanism of interaction of few selected different classes of pesticides, namely, λ-cyhalothrin, imidacloprid, and metsulfuron-methyl toward these hybrids. Individually, to study this comparative binding when hybrids are not used, the understanding of preferred binding toward any of these selected compounds could be challenging, costly, and time-consuming. Dynamic light scattering (DLS) is used to study the changes observed for hydrodynamic radius and zeta potential for the stability of the resulting products. This simple method can also be extended to identify the binding mechanism for other diverse set of combinations. These studies are supported by binding of GO with nanoparticles in batch adsorption and the best fit using Langmuir and Freundlich isotherms is presented. Moreover, pesticide adsorption toward GO-nanoparticle composites is also evidenced.

Food safety and quality assessment: comprehensive review and recent trends in the applications of ion mobility spectrometry (IMS)

Ion mobility spectrometry (IMS) is an analytical separation and diagnostic technique that is simple and sensitive and a rapid response and low-priced technique for detecting trace levels of chemical compounds in different matrices. Chemical agents and environmental contaminants are successfully detected by IMS and have been recently considered to employ in food safety. In addition, IMS uses stand-alone or coupled analytical diagnostic tools with chromatographic and spectroscopic methods. Scientific publications show that IMS has been applied 21% in the pharmaceutical industry, 9% in environmental studies and 13% in quality control and food safety. Nevertheless, applications of IMS in food safety and quality analysis have not been adequately explored. This review presents the IMS-related analysis and focuses on the application of IMS in food safety and quality. This review presents the important topics including detection of traces of chemicals, rate of food spoilage and freshness, food adulteration and authenticity as well as natural toxins, pesticides, herbicides, fungicides, veterinary, and growth promoter drug residues. Further, persistent organic pollutants (POPs), acrylamide, polycyclic aromatic hydrocarbon (PAH), biogenic amines, nitrosamine, furfural, phenolic compounds, heavy metals, food packaging materials, melamine, and food additives were also examined for the first time. Therefore, it is logical to predict that the application of the IMS technique in food safety, food quality, and contaminant analysis will be impressively increased in the future. HighlightsCurrent status of IMS for residues and contaminant detection in food safety.To assess all the detected contaminants in food safety, for the first time.Identified IMS-related parameters and chemical compounds in food safety control.

Rapid ultrasound-assisted microextraction of atorvastatin in the sample of blood plasma by nickel metal organic modified with alumina nanoparticles

In the present work, nickel-1,4-benzenedioxyacetic acid was synthesized as a rod-like metal organic material and then modified with alumina nanoparticles to synthesize nickel metal organic modified-Al₂ O₃ nanoparticles. The material was found as an efficient sorbent for the enrichment of atorvastatin in human blood plasma. After the extraction of the sample of plasma by ultrasound-assisted dispersive solid phase extraction, high performance liquid chromatography-ultraviolet was used to determine the quantitatively pre-concentrated interest analyte. The conditions for optimum extraction were achieved by the optimization of the volume of eluent, dosage of the sorbent, and time of sonication. Solution pH of 7.0, 250 μL of ethanol, 45 mg of the sorbent, and 10 min of sonication time were the conditions for extracting the atorvastatin maximum recovery of higher than 97.0%. By using desirability function for the optimization of the process, the present method showed a response that was linear ranging from 0.2 to 800 ng/mL with regression coefficient of 0.999 in the plasma of human blood with a satisfactory detection limit of 0.05 ng/mL, while the precision of interday for the current method was found to be <5%. It can be concluded that dispersive solid phase extraction method is effective for the extraction of atorvastatin from human plasma samples (97.4-102%) due to its easy operation, simplicity, repeatability, and reliability.

Magnetic solid-phase extraction based on magnetic amino modified multiwalled carbon nanotubes for the fast determination of seven pesticide residues in water samples

A rapid and simple analytical method based on magnetic solid-phase extraction with magnetic amino modified multiwalled carbon nanotubes with ultra-high performance liquid chromatography-tandem mass spectrometry is reported for the determination of seven pesticides (futriafol, metalaxyl, myclobutanil, napropamide, epoxiconazole, fipronil and diniconazole) in water samples. In this study, magnetic amino modified multi-walled carbon nanotubes were synthesized and selected as a new kind of material to adsorb pesticides in the water samples. Various magnetic solid-phase extraction parameters, such as the amount and type of adsorbent, extraction methods, extraction time, the type and volume of desorption solvent, desorption time and solution ionic strength, were systematically optimized. Under optimum conditions, the method validation results showed good linearity and recoveries. The calibration curves were in the range of 1.0-100 ng mL-1 for napropamide, epoxiconazole, metalaxyl, and fipronil, while they were 5.0-500 ng mL-1 for futriafol, myclobutanil, and diniconazole, with determination coefficients (R2) higher than 0.9909. The limits of quantification were 1.0-5.0 ng mL-1 and the limits of detection were 0.3-1.5 ng mL-1. The recoveries of the seven pesticides ranged from 80.4% to 103.2%. This developed method, which is more convenient and effective in comparison with traditional methods, has been successfully applied for the analysis of pesticides in water samples qualitatively and quantitatively.

Fabrication of chromium-imprinted polymer: a real magneto-selective sorbent for the removal of Cr(vi) ions in real water samples

Graphical representation (a and b) show the procedure for the synthesis of Cr(vi) ion-imprinted magnetic polymer.

Magnetic molecularly imprinted polymers for the detection of aminopyralid in milk using dispersive solid-phase extraction

A method for dummy molecular imprinting-magnetic dispersive solid-phase extraction (MI-MDSPE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the selective determination of aminopyralid in milk. The magnetic material and polymers were combined via a series of modifications in Fe3O4. Fe3O4@SiO2-NH2@MIP, Fe3O4@SiO2-COOH@MIP and two types of aminopyralid-specific magnetic molecularly imprinted polymers (MMIPs) were prepared on the surface of magnetic nanoparticles modified with amino and carboxyl groups. The morphology and magnetic properties of the polymer were characterized. Fe3O4@SiO2-NH2@MIP exhibits not only good dispersibility and magnetic properties, but also an outstanding recognition pattern to the target analyte. Adsorption experiments demonstrated that Fe3O4@SiO2-NH2@MIP, with a high specific surface area and fast mass transfer rate, had a higher affinity than Fe3O4@SiO2-COOH@MIP towards aminopyralid. Under the optimized MI-MDSPE conditions, the method had good linearity (R 2 > 0.9972), excellent recoveries (83.3-90%), and good precision (relative standard deviations (RSDs) < 12.6%). This method has limits of detection (LOD) and quantification (LOQ) of 0.231 and 0.77 μg kg-1, respectively, indicating that these MMIPs can be used to analyse trace levels of aminopyralid in real samples.

A green triple-locked strategy based on volatile-compound imaging, chemometrics, and markers to discriminate winter honey and sapium honey using headspace gas chromatography-ion mobility spectrometry

A simple and environmentally approach using untargeted imaging of volatile substances combined with chemometrics and markers response was proposed for discriminating different species of honey with headspace gas-chromatography-ion-mobility (HS-GC-IMS). The 3D HS-GC-IMS imaging and their response differences enabled the clear discrimination between winter honey and sapium honey. Principal component analysis (PCA) and partial least-squares discrimination analysis (PLS-DA) were employed to discriminate different honey. Markers of two kinds of honey were identified and confirmed with a user-built imaging database combined with multivariate analysis. Benzaldehyde dimer and phenylacetaldehyde dimer were found to be reliable markers of winter honey, and phenylethyl acetate dimer was of sapium honey. Adulteration identification of the honey samples with different adulteration ratios were subjected to this triple-locked strategy analysis. The results demonstrate that HS-GC-IMS imaging coupled with chemometrics and marker identification is a useful triple-locked strategy to discriminate honey from different floral origins and adulterated honey.

Preconcentration and Determination of Psychotropic Drugs in Urine Samples by Ion Mobility Spectrometry with Electrospray Ionization Coupling On-Line Single-Drop Liquid-Liquid-Liquid Microextraction

A method for analysis of psychotropic drugs in urine is investigated using a novel single-drop liquid-liquid-liquid microextraction (SDLLLME) apparatus as an electrospray emitter in ion mobility spectrometry (IMS). In this method, ketamine and pethidine are back-extracted into the acceptor phase (water and methanol) from the water and methanol immiscible organic phase. Sensitivity of extraction is improved as it does not require further methanol-adding procedure. Factors affecting the extraction of psychotropic drugs are characterized, including organic solvent type, extraction time, and concentration of NaOH/Ac in the donor/acceptor phase. The best extraction sensitivity is obtained with 600 μL dodecane as the organic phase, 30 minutes extraction time, and 10 mL donor phase with 0.01 M sodium hydroxide (NaOH) and 3 μL acceptor phase with 0.5 M acetic acid (Ac). Using this method, the two analytes can be extracted and analyzed simultaneously, showing this method is valuable for field application.

Trace analysis by ion mobility spectrometry: From conventional to smart sample preconcentration methods. A review

Ion mobility spectrometry (IMS) is a rapid and high sensitive technique widely used in security and forensic areas. However, a lack of selectivity is usually observed in the analysis of complex samples due to the scarce resolution of the technique. The literature concerning the use of conventional and novel smart materials in the pretreatment and preconcentration of samples previous to IMS determinations has been critically reviewed. The most relevant strategies to enhance selectivity and sensitivity of IMS determinations have been widely discussed, based in the use of smart materials, as immunosorbents, aptamers, molecularly imprinted polymers (MIPs), ionic liquids (ILs) and nanomaterial. The observed trend is focused on the development of IMS analytical methods in combination of selective sample treatments in order to achieve quick, reliable, sensitive, and selective methods for the analysis of complex samples such as biological fluids, food, or environmental samples.

Study on Mobility, Distribution and Rapid Ion Mobility Spectrometry Detection of Seven Pesticide Residues in Cucumber, Apple, and Cherry Tomato

This research explores the mobility and distribution rules of simazine, acetamiprid, hexazinone, paclobutrazol, amitraz, clofentezine, and boscalid in the pulp and peel of apple, cucumber, and cherry tomato. A laboratory test was carried out by treating the matrices with standard solution for different periods of time. The percentage sorption of pesticides ranged from 0.02 to 89.3% for the three matrices. The pesticides' distribution was also determined, and all pesticides showed ratio values (Q) between pulp and peel concentrations in the three matrices of <0.8, which proved that the highest pesticides' content was found in the peel. In addition, a rapid and simple process combining a surface swab capture method and pulse glow discharge-ion mobility spectrometry (PGD-IMS) detection was established for the detection of pesticides on matrix surfaces. In the swab method, the whole matrix surface was swabbed manually by swab sticks, and swab sticks were agitated in acetonitrile to release the pesticides. The releasing factors of pesticides in the three matrices were calculated. The linearity, LOD, LOQ, and matrix effect were investigated to assess the applicability of the swab-IMS process in practical analysis. The swab-IMS method is rapid, sensitive, and quantitative and can be achieved in the field.