A new sustainable filtration membrane extraction method based on nanoconfined liquid phase extraction: Determination of organochlorinated pesticides and pyrethroids in tea samples.

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).

Effect of Growth Stage on Nutrition, Fermentation Quality, and Microbial Community of Semidry Silage from Forage Soybean.

Soybean (Glycine max (Linn.) Merr.) is highly suitable as animal feed. The silage quality and microbial characteristics of soybean silage are still unclear. Forage soybean (HN389), at six different growth stages (R2-R7), were used as experimental materials to investigate the changes in fermentation, nutritional quality, and microbial characteristics of semidry silage after 0, 7, 14, 30, and 45 d. As the growth period extended, the content of crude protein (CP) and crude fat (EE) gradually increased, while the neutral detergent fiber (NDF) and the acid detergent fiber (ADF) content decreased. The pH value also decreased gradually with fermentation time, accompanied by increases in the proportion of ammonia-N and the content of lactic acid (LA) and acetic acid (AA). In addition, competitive inhibition was observed in the microbial fermentation. With the process of ensiling, Lactobacillus became the dominant bacterial species. The results indicate that the most active stage of fermentation during ensiling occurred within the first 7 days, the fermentation and nutritional quality of the soybean forage were improved, and the optimal mowing stage was the grain stage. Comparison of the microbial abundance showed that all microorganisms entered a stable stage at 30 days of silage. After storage, the dominant bacteria were Lactobacillus, Enterobacter, and Pantoea.

Highly sensitive analysis of photoregulation and dynamic distribution of phytohormones based on nanoconfined liquid phase nanoextraction.

BACKGROUND: As a vital energy source, light is one of the most significant environmental signals for plants' growth and development. The crosstalk amongst phytohormones regulated by light exhibits quantitative dynamic changes, but methodologies to analyze their distribution during plant growth are still limited. Rapid, highly sensitive, low-invasive detection and simultaneous assessment of the levels of multiple classes of phytohormones have important phytology applications, however the existing sample pretreatment strategies remain intricate, laborious, and far from being developed for in vivo high-sensitivity testing. (81) RESULTS: We applied a nanoconfined liquid phase nanoextraction (NLPNE) technique based on acidified carbon nanofibers (ACNFs) in combination with LC-ESI-MS/MS for highly sensitive analysis of acidic phytohormones' photoregulation and dynamic distribution. In this system, the mass transfer ability of analytes entering the nanoconfined space is significantly improved given the nanoconfined effect. In particular, the accelerated and strong adsorption of alkaline compounds to the ACNFs surface provide minimum interference for acidic compounds (photosensitive phytohormones), which facilitates their simple, fast, and selective quantification with improved sensitivity. The ACNFs-NLPNE strategy achieved quantitative enrichment of multi-class phytohormones in less than 5 min, and detection limits down to 0.49 fg mL-1. Moreover, we monitored the phytohormone changes under red and blue monochromatic light with relative standard deviations <13.4 %. The results further indicated that short-time red light regulation promoted Lepidium sativum L. growth while blue light inhibited it. (141) SIGNIFICANCE: A nanoconfinement effect-based sample pretreatment platform was developed for monitoring photoregulation phytohormones dynamic distribution with higher sensitivity and stability. Our findings highlighted the importance of the NLPNE approach in providing an accurate plant crosstalk information at the molecular level, which opens a promising avenue for investigating internal hormonal responses to external stimuli. (52).

Fast removal of phenolic compounds from water using hierarchical porous carbon nanofibers membrane.

Water pollution is becoming increasingly serious and seriously endangering human health, especially the direct emissions of phenolic compounds. An integrated sample pre-treatment and derivatization method based on a biopolymers/TEOS-based carbon nanofibers microextraction that allows rapid extraction (5 min), followed by separation and highly sensitive detection of phenolic compounds by gas chromatography‒mass spectrometry (GC-MS) analysis, is described. The developed methodology, coupled with GC-MS, allowed low detection limits (0.03-0.32 ng mL‒1), good linearities (0.5-200 ng mL‒1) and recoveries (73.58-85.76%) to be achieved in a few steps and short time. Based on the high adsorption properties of materials, the on-line removal device of phenolic compounds in water was designed. The elimination rate of phenolic compounds in water was higher than 73.58% at 1 mL min‒1 and three cycles. The elimination strategy for the phenolic compounds is very versatile and is easy to apply.

NLow matrix effect pretreatment method based on gas-liquid micro-extraction technique for determining multi-class pesticides in crops.

A low matrix effect pretreatment method by Gas-liquid microextraction technique (GLME) combined with ultrasound assisted extraction (UAE-GLME) has been developed for fast analysis of 41 multi-class pesticides in different crop samples. Extraction and cleanup procedures were completed within 20 min, and the impact of matrix effects in potato, lentil, corn and soybean matrices were systematically evaluated. As high as 97.6% pesticides treated by UAE-GLME experienced low matrix effect, and up to 99% pesticides except parathion-methyl in lentil samples were categorized as medium matrix effect. Good trueness (recoveries of 61.3-115.8%) and precision (RSD≤20%) were demonstrated by the UAE-GLME method, with MLOQs ranged from 0.005 to 0.02 mg kg-1. This method detected 2-phenylphenol, pyrimethanil, triadimefon and tebuconazole in the range of 0.008-0.012 mg kg-1 in real food samples. The multiresidue analysis feature of GLME has been validated, which displays further potential for high-throughput determination of organic pollutants in foods with distinctive properties.

Ex-situ and in-situ rapid and quantitative determination of benzene derivatives in seawater using nanoconfined liquid phase nanoextraction.

Benzene derivatives (BDs) constitute a class of environmental pollutants whose exposure poses a grave risk to human health. These compounds rapidly diffuse from the atmosphere to the marine ecosystem: for this reason, their monitoring in seawater is every day more compelling. In this work, nanoconfined liquid phase nanoextraction (NLPNE), a versatile extraction technique recently described, has been for the first time applied to the gas chromatographic mass spectrometry (GC/MS) analysis of BDs in seawater. Ex-situ and in-situ NLPNE procedures have been developed and optimized in terms of extraction capabilities, analysis time, precision, and accuracy. Compared to the traditional extraction procedures, based on solid-phase microextraction (SPME) and liquid-liquid extraction (LLE), the proposed NLPNE methods allowed a rapid on-site analysis of benzene compounds with low solvent consumption, higher enrichment factors, and improved automation grade. Determination coefficients ranging from 0.9929 to 0.9997 were obtained for all BDs in the range 0.10-500 ng mL-1 and 5.00-500 ng mL-1, for ex-situ and in-situ NLPNE, respectively. Ex-situ and in-situ limits of detection ranged from 0.2 to 7.6 ng mL-1 and 0.04-1.00 ng mL-1. Our results suggest that NLPNE coupled to GC-MS can be considered a powerful technique for high-throughput analyses of trace compounds in environmental, food and biological samples.

Carbon Nanofibers-Based Nanoconfined Liquid Phase Filtration for the Rapid Removal of Chlorinated Pesticides from Ginseng Extracts.

A rapid nanoconfined liquid phase filtration system (NLPF) based on solvent-confined carbon nanofibers/carbon fiber materials (CNFs/CFs) was proposed to effectively remove chlorinated pesticides from ginsenosides-containing ginseng extracts. A series of major parameters that may affect the separation performance of the CNFs-NLPF method were extensively investigated, including the water solubility of nanoconfined solvents, filtration rate, ethanol content of the ginseng extracts, and reusability of the material for repeated adsorption. The developed method showed a high removal efficiency of pesticides (85.5-97.5%), high retainment rate of ginsenosides (95.4-98.9%), and consistent reproducibility (RSD < 11.8%). Furthermore, the feasibility of the CNFs-NLPF technique to be scaled-up for industrial application was systematically explored by analyzing large-volume ginseng extract (1 L), which also verified its excellent modifiable characteristic. This filtration method exhibits promising potential as a practical tool for removing pesticide residues and other organic pollutants in food samples to assure food quality and safeguard human health.

Across-polarity quantification method for broad metabolome coverage based on consecutive nanoconfined liquid phase nanoextraction technology: Application in discovering the plasma potential biomarkers of different types of cancer.

LC-MS-based metabolomics offers the potential of discovering biomarkers and exploring the mechanisms of underlying diseases. However, given the enormous polarity difference between metabolites, simultaneous across-polarity quantification for broad metabolome coverage has still been challenged by limited sample preparation methods and other hurdles. Herein, we proposed a consecutive extraction strategy based on nanoconfined liquid phase nanoextraction (NLPNE) technique. By modulating the nanoconfined solvents and coupling with LC-MS/MS, this method could simultaneously quantify metabolites with different polarities assigned to three classes, including amines (high polarity), steroids (middle polarity) and lysophosphatidylcholines (LPCs, low polarity) with high selectivity and high efficiency. During the systematical optimization of the extraction workflow, response surface methodology (RSM) was used for key parameters optimization. And consecutive extraction mode and parallel extraction mode were proposed in the choice of integrated extraction strategy. Then the consecutive NLPNE method was compared with two conventional sample preparation methods in metabolomics, protein precipitation (PP) and liquid-liquid extraction (LLE). After systematical validation, the consecutive NLPNE method coupled with LC-MS/MS was successfully applied in the identification of multi-metabolites indexes for lung, colorectal, and gastric cancer plasma samples from healthy controls, and among different types of cancer with student's t-test, partial least squares discriminant analysis (PLS-DA) and logistic regression-receiver operating characteristic (ROC) curve analysis. Taken together, the developed methodology is a versatile candidate in metabolomics for high coverage detection and may be used as a powerful tool for cancer diagnosis.

Nanoconfined Liquid Phase Nanoextraction Based on Carbon Nanofibers.

An innovative and versatile microextraction technique based on nanoconfined solvent on carbon nanofibers has been conceived, realized, optimized, and presented here. The extraction capabilities of this technique toward polar, medium polar, and/or nonpolar substances can be easily modulated based on the nanoconfined solvent used. The so-called nanoconfined liquid phase nanoextraction showed excellent characteristics in terms of extraction recoveries, extraction time (≤1 min), reliability, and versatility. A needle-tip device has been realized on the base of this extraction process to allow direct extraction procedures and minimally invasive testing: this device guarantees a safe insertion in aqueous or soft samples, and it allows a fast and minimally invasive analyte extraction. Due to its versatility, chemical stability, and mechanical flexibility, nanoconfined liquid phase nanoextraction can be considered a powerful candidate for high-throughput analyses of biological samples.

Simultaneous determination of multiple phytohormones in tomato by ionic liquid-functionalized carbon fibers-based solid-phase microextraction coupled with liquid chromatography-mass spectrometry.

Phytohormones are interrelated by synergistic or antagonistic crosstalk and play important roles in the regulation of plant growth and development. In order to understand the interaction between phytohormones in the plant physiological network, it is necessary to determine trace levels of multiple phytohormones simultaneously in a complex matrix. Here, we synthesized ionic liquids containing different functional groups and modified the surface of carbon fibers with them. Based on these carbon fibers-ionic liquid (CFs-IL) materials, a solid phase microextraction method was developed to enable the simultaneous extraction of phytohormones. The adsorption specificity of multiple phytohormones was studied by identifying the hydrophobic, electrostatic, and π-π interactions, as well as hydrogen bonds, which favor simultaneous extraction of the relevant acidic, alkaline and neutral phytohormones by improving compatibility. The proposed method, coupled with liquid chromatography-tandem mass spectrometry, was applied to the simultaneous determination of 13 acidic, alkaline and neutral phytohormones in tomato. The limits of quantification were found to be in the range of 0.32-54.05 ng mL-1 and 4.6-185.8 pg mL-1, respectively, when measured by QQQ and Q-TOF. All of the relative recoveries were in the range of 94.40-113.37% with RSDs ≤15.36% (n = 3) for spiked tomato samples. This method is expected to be widely applied to multiple phytohormones analysis for in-depth researches concerning the physiological networks of plants.

Recent developments and emerging trends of mass spectrometric methods in plant hormone analysis: a review.

Plant hormones are naturally occurring small molecule compounds which are present at trace amounts in plant. They play a pivotal role in the regulation of plant growth. The biological activity of plant hormones depends on their concentrations in the plant, thus, accurate determination of plant hormone is paramount. However, the complex plant matrix, wide polarity range and low concentration of plant hormones are the main hindrances to effective analyses of plant hormone even when state-of-the-art analytical techniques are employed. These factors substantially influence the accuracy of analytical results. So far, significant progress has been realized in the analysis of plant hormones, particularly in sample pretreatment techniques and mass spectrometric methods. This review describes the classic extraction and modern microextraction techniques used to analyze plant hormone. Advancements in solid phase microextraction (SPME) methods have been driven by the ever-increasing requirement for dynamic and in vivo identification of the spatial distribution of plant hormones in real-life plant samples, which would contribute greatly to the burgeoning field of plant hormone investigation. In this review, we describe advances in various aspects of mass spectrometry methods. Many fragmentation patterns are analyzed to provide the theoretical basis for the establishment of a mass spectral database for the analysis of plant hormones. We hope to provide a technical guide for further discovery of new plant hormones. More than 140 research studies on plant hormone published in the past decade are reviewed, with a particular emphasis on the recent advances in mass spectrometry and sample pretreatment techniques in the analysis of plant hormone. The potential progress for further research in plant hormones analysis is also highlighted.

Recent trends in analytical methods for water-soluble vitamins.

In this review, recent advances in the analysis of water-soluble vitamins (WSVs) have been reported considering the advantages and disadvantages of various extraction, separation and detection techniques, commonly used for their quantification. Acid hydrolysis, enzyme treatment, SPE based methods and some other extraction methods have been discussed. Particular attention has been devoted to the analytical techniques based on liquid chromatography and electrophoresis. Furthermore, suitability and selectivity of hydrophilic interaction liquid chromatography (HILIC) for WSVs has been discussed in detail. Problems related to these techniques and their possible solutions have also been considered. Special focus has been given to the applications of liquid chromatography (since 2014-2019) for the simultaneous analysis of WSVs and their homologous in complex food samples.

Fast on-fiber derivatization and GC/MS analysis of phytohormones in wheat based on pencil-type coated carbon fibers.

New coated carbon fibers (CCFs) have been synthesized, characterized and used as solid phase microextraction (SPME) matrix for the analysis of phytohormones (jasmonic acid, indole-3-acetic acid, and abscisic acid) in wheat samples. The SPME device, realized inserting CCFs in a pencil-type device, when coupled with gas chromatography-mass spectrometry, provides in few steps high recovery values (79-112%), fast on-fiber derivatization (30 s), good method reproducibility (RSD < 20%), low detection limits (0.5-2.1 ng g-1). The pencil-type CCFs-SPME device was successfully employed for the determination of phytohormone in wheat samples, allowing simple and quick extraction/derivatization/injection processes. The proposed device can be then considered as a promising and functional tool for fast and reliable extraction and preconcentration of analytes from real samples, allowing a simple derivatization procedure and direct injection in the chromatographic instrumentation.

[One-step extraction method of phthalate esters in vegetable oils].

In order to develop a fast investigation method for phthalate esters (PAEs) from vegetable oils, a gas-liquid micro-extraction (GLME) technique that combined with GC-MS was established. A vegetable oil sample (0.1 g) was directly added into the GLME device. The integrated process of extraction, clean-up, and concentration of PAEs was completed within 5 min. Internal standard method was applied to ensure the accuracy of the results. Soybean oil, blend oil, olive oil, and sesame oil were spiked with 200 µg/kg of a mixed 15 PAEs standard, and the ranges of the recoveries and RSDs were between 60.0% to 112.3% and 0.9% to 28.4%, respectively. Compared with some traditional sample pretreatment methods such as liquid-liquid extraction, liquid-liquid micro-extraction, gel permeation chromatography, this method is simple and fast, with high accuracy, good repeatability and low matrix effect. This study verified the suitability of the GLME method for field detection of food products in food safety sector and exhibits great significance for the completion of food safety system in China.

Complete mitochondrial genomes of Anopheles stephensi and An. dirus and comparative evolutionary mitochondriomics of 50 mosquitoes.

To better understand the phylogeny and evolution of mosquitoes, the complete mitochondrial genome (mitogenome) of Anopheles stephensi and An. dirus were sequenced and annotated, and a total of 50 mosquito mitogenomes were comparatively analyzed. The complete mitogenome of An. stephensi and An. dirus is 1,5371 bp and 1,5406 bp long, respectively. The main features of the 50 mosquito mitogenomes are conservative: 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, positive AT-skew and negative GC-skew. The gene order trnA-trnR in ancestral insects is rearranged. All tRNA genes have the typical clover leaf secondary structure but tRNA Ser . The control regions are highly variable in size. PCGs show signals of purifying selection, but evidence for positive selection in ND2, ND4 and ND6 is found. Bayesian and Maximum Likelihood phylogenetic analyses based on all PCG nucleotides produce an identical tree topology and strongly support the monophyly of subgenera Cellia, Anopheles, Keterszia and Nyssorhynchus, the sister relationship of the subgenera Nyssorhynchus and Keterszia, and Cellia and Anopheles. The most recent ancestor of the genus Anopheles and Culicini + Aedini exited ~145 Mya ago. This is the first comprehensive study of mosquito mitogenomes, which are effective for mosquito phylogeny at various taxonomic levels.

A high throughput mass spectrometry screening analysis based on two-dimensional carbon microfiber fractionation system.

A novel high-throughput, solvent saving and versatile integrated two-dimensional microscale carbon fiber/active carbon fiber system (2DµCFs) that allows a simply and rapid separation of compounds in low-polar, medium-polar and high-polar fractions, has been coupled with ambient ionization-mass spectrometry (ESI-Q-TOF-MS and ESI-QqQ-MS) for screening and quantitative analyses of real samples. 2DµCFs led to a substantial interference reduction and minimization of ionization suppression effects, thus increasing the sensitivity and the screening capabilities of the subsequent MS analysis. The method has been applied to the analysis of Schisandra Chinensis extracts, obtaining with a single injection a simultaneous determination of 33 compounds presenting different polarities, such as organic acids, lignans, and flavonoids in less than 7min, at low pressures and using small solvent amounts. The method was also validated using 10 model compounds, giving limit of detections (LODs) ranging from 0.3 to 30ngmL-1, satisfactory recoveries (from 75.8 to 93.2%) and reproducibilities (relative standard deviations, RSDs, from 1.40 to 8.06%).