Tobacco Samples Research Articles

Identification of two novel poleroviruses and the occurrence of Tobacco bushy top disease causal agents in natural plants

Tobacco bushy top disease (TBTD) is a devastating tobacco disease in the southwestern region of China. TBTD in the Yunnan Province is often caused by co-infections of several plant viruses: tobacco bushy top virus (TBTV), tobacco vein distorting virus (TVDV), tobacco bushy top virus satellite RNA (TBTVsatRNA) and tobacco vein distorting virus-associated RNA (TVDVaRNA). Through this study, two new poleroviruses were identified in two TBTD symptomatic tobacco plants and these two novel viruses are tentatively named as tobacco polerovirus 1 (TPV1) and tobacco polerovirus 2 (TPV2), respectively. Analyses of 244 tobacco samples collected from tobacco fields in the Yunnan Province through RT-PCR showed that a total of 80 samples were infected with TPV1 and/or TPV2, and the infection rates of TPV1 and TPV2 were 8.61% and 29.51%, respectively. Thirty-three TPV1 and/or TPV2-infected tobacco samples were selected for further test for TBTV, TVDV, TBTVsatRNA and TVDVaRNA infections. The results showed that many TPV1 and/or TPV2-infected plants were also infected with two or more other assayed viruses. In this study, we also surveyed TBTV, TVDV, TBTVsatRNA and TVDVaRNA infections in a total of 1713 leaf samples collected from field plants belonging to 29 plant species in 13 plant families and from 11 provinces/autonomous regions in China. TVDV had the highest infection rates of 37.5%, while TVDVaRNA, TBTV and TBTVsatRNA were found to be at 23.0%, 12.4% and 8.1%, respectively. In addition, TVDV, TBTV, TBTVsatRNA and TVDVaRNA were firstly detected of co-infection on 10 plants such as broad bean, pea, oilseed rape, pumpkin, tomato, crofton weed etc., and 1 to 4 of the TBTD causal agents were present in the samples collected from Guizhou, Hainan, Henan, Liaoning, Inner mongolia and Tibet autonomous regions. The results indicated that TBTD causal agents are expanding its host range and posing a risk to other crop in the field.

Highly selective and responsive detection of simetryn in tobacco samples based on molecularly imprinted photonic crystal hydrogels

A novel sensor was developed based on the combination of photonic crystal templating and molecular imprinting technique (MIT) for the detection of simetryn in tobacco samples. The molecularly imprinted photonic crystal hydrogels (MIPHs) was prepared with methacrylic acid (MAA) as monomers, ethylene glycol dimethylacrylate (EGDMA) as cross-linkers, simetryn as imprinting template molecules and polystyrene (PS) microspheres as photonic crystal template. The ordered three-dimensional macro-porous structure of MIPHs with simetryn imprinting template can generate Bragg diffraction, showing a bright structural color. The results show that the MIPHs have high selectivity and excellent sensing performance and can be used for the detection of simetryn from actual tobacco samples. Among the four triazine herbicides with similar structure, MIPHs only produced obvious Bragg diffraction peak wavelength change to simetryn, and MIPHs have good recoverability with four cycle times. When the concentration of simetryn in the actual tobacco increased from 0 to 1.0 μg/mL, the wavelength was red-shifted from 457 nm to 499 nm, which was in the blue and green visible light wavelength range. This new sensor is expected to be used to directly detect pesticide residues in tobacco.

Highly sensitive time-resolved fluoroimmunoassay for the quantitative onsite detection of Alternaria longipes in tobacco.

Alternaria longipes is a causal agent of brown spot of tobacco, which remains a serious threat to tobacco production. Herein, we established a detection method for A. longipes in tobacco samples based on the principle of time-resolved fluoroimmunoassay, in order to fulfil the requirement of rapid, sensitive and accurate detection in situ. A monoclonal antibody against A. longipes was generated, and its purity and titration were assessed using western blot and ELISA. The size of europium (III) nanospheres was measured to confirm successful antibody conjugation. The method described here can detect A. longipes protein lysates as low as 0.78ngml-1 , with recovery rates ranging from 85.96% to 99.67% in spiked tobacco. The specificity was also confirmed using a panel of microorganisms. The fluorescent strips allow rapid and sensitive onsite detection of A. longipes in tobacco samples, with high accuracy, specificity, and repeatability. This novel detection method provides convenience of using crude samples without complex procedures, and therefore allows rapid onsite detection by end users and quick responses towards A. longipes, which is critical for disease control and elimination of phytopathogens.

A Survey of Five Plant Viruses in Weeds and Tobacco in Poland

Weeds may contribute to the spread of plant virus epidemics by acting as reservoirs of viruses or/and their vectors. The aim of this research was to study the prevalence of five viral pathogens in weeds in the fields of solanaceous crops in six provinces in Poland differing with soil and climate conditions. Most of the sampled sites were associated with tobacco production. The total number of 157 samples of tobacco and 600 samples of weeds were subjected to DAS-ELISA detection of tomato spotted wilt orthotospovirus (TSWV), cucumber mosaic virus (CMV), potato virus Y (PVY), tobacco mosaic virus (TMV) and tobacco ringspot virus (TRSV). Twenty nine percent of samples of weeds were infected with at least one virus. TSWV and TMV were the most frequently detected in 17.5% and 14.7% of samples, respectively. In most provinces where infected tobacco was found, the same virus was also detected in weeds. Results of this survey are discussed in the context of the current status of virus epidemics in tobacco fields in Poland.

Deep eutectic solvents based on carboxylic acids for metals separation from plant samples: Elemental analysis by ICP-OES

Deep eutectic solvents based on choline chloride, carboxylic acids, urea, and polyols were investigated for separation of 14 metals from plant samples. It was found that carboxylic acid as precursor of DES played key-role for effective metals separation. It was established that the solvent synthesized from choline chloride and malic acid provided highest extraction recovery (from 73 to 88%). Mixing and heating the solvent and sample for 30 min at a temperature of 70 °C provided effective separation of metals from plant sample. The developed procedure is not required a microwave digestion of samples. After separation the solvent phase containing analytes was dissolved in aqueous phase and analyzed. The developed procedure was applied to elemental analysis of plant tobacco and lettuce samples by inductively coupled plasma optical emission spectroscopy. Limits of detection calculated as three times the signal-to-noise ratio were in the range from 0.2 to 17 mg kg−1.

ФОРМУВАННЯ РОБОЧОЇ КОЛЕКЦІЇ ТЮТЮНУ ЗА КОМПЛЕКСОМ ОЗНАК В УМОВАХ ЦЕНТРАЛЬНОГО ЛІСОСТЕПУ УКРАЇНИ

One of the effective ways of creating high-yield tobacco varieties is the selection of donors of economically valuable characters and their optimal combination in new plant genotypes. Sources for selection and creation of such donors are gene pool collections, which concentrate source material of different geographical origin with a set of valuable breeding and genetic characters. The level of expression of these characters is modified by breeding conditions and the response of the genotype to environmental factors. Therefore, the main purpose of our research was to study the manifestation of morpho-biological features and properties of plants of tobacco collection samples in agroclimatic conditions of the Central Forest-steppe of Ukraine, establishment of breeding value of available gene pool of culture, selection of sources of economically valuable characters and formation of working tobacco collection. The strategic task of research is to create the varieties that are able to maximize the use of their genetic potential in a specific region, to be resistant to stressful environmental conditions, to ensure a high realization of the genetic potential of productivity. For the first time in the conditions of the Central Forest-steppe of Ukraine the analysis of 30 collection samples of tobacco of different ecological and geographical origin was carried out. New genetic sources for morphological character of plants, raw yield, seed productivity and early maturity, which are used at the Experimental station of tobacco farming National Research Center "Institute of Agriculture of the National Academy of Agrarian Sciences" in variety breeding, were identified. A certificate of registration of the working collection of tobacco gene pool of the present on morphological characters was received from the National Center for Plant Genetic Resources of Ukraine, according to the results of research in 2017–2019 (Certificate № 277 from 29.10.2019).

Identification characteristics of non-smoking tobacco products

Modern trends in the reduction of cigarette consumption have led to the spread of smokeless tobacco and non-tobacco nicotine-containing products [1]; their variety creates certain problems with the identification of products in this segment. Sucking tobacco (snus) has been banned in the Russian Federation for wholesale and retail trade since 2015, but it is a product similar to chew- ing tobacco in packaging, ingredient composition and physiological effects. Therefore, establishing the identification characteristics of chewing tobacco is an urgent task. The attitude towards chewing tobacco is controversial. The absence of the smoldering / burning process characteristic of cigarettes indicates a decrease in the harmful effect on the human body. At the same time, the physiological ef- fect on the consumer is based on the effect of nicotine extracted from tobacco through the oral mucosa. Consumer indicators of samples of smokeless tobacco / non-tobacco nicotine-containing products have been investigated: moisture content, fractional composition and nicotine content. The moisture content of samples of non-smoking products ranges from 19,0 % to 36,5 %. The nicotine content in the investigated tobacco / non-tobacco products is 0,3–2,4 % / 1,0–8,8 % respectively. To establish the identification signs of smokeless tobacco products the following methods have been used: product fractionation, optical microscopy, spectrophotometry, and liquid chromatography / tandem mass spectrometry (LCMS / MS). The main feature of the difference between smokeless tobacco products and non-tobacco nicotine-containing products has been determined – the presence of tobacco in the ingredient composition, confirmed by the structure of the product and the content of specific tobacco nitrosamines. As a result of the research, experimental data were obtained on the quantitative determination of the content of tobacco specific nitrosamines by the LCMS / MS method in smokeless tobacco products. The main identification feature of chewing tobacco has been established: the presence of raw tobacco in the ingredient composition with a coarse fraction content is at least 15 %.

Preparation and application of highly sensitive myclobutanil sensor based on molecularly imprinted photonic crystals

In this paper, the myclobutanil (MYC) molecularly imprinted photonic crystal hydrogels sensor (MYC-MIPHS) was prepared by thermal polymerization with SiO2 microspheres as the substrate, MYC as the template molecule, 2-(Trifluoromethyl) acrylic acid (TFMAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, analytical-grade 2,2-azobis-(2-isobutyronitrile) (AIBN) as the initiator and methanol as the solvent. The MYC-MIPHS had the characteristics of low cost, high stability and special recognition, and could be used to detect MYC in tobacco samples pretreated by MYC-MISPE (molecularly imprinted solid phase extraction), the diffraction peak of the MYC-MIPHS was rapidly red-shifted in the liquid with MYC and its analogs. It could realize the semi-qualitative detection of MYC within 18min by UV–Vis, and an MIPHS method for MYC detecting in tobacco was established.

Microbiology of the American Smokeless Tobacco.

Smokeless tobacco products (STP) contain diverse microbial communities that contribute to the formation of harmful chemical byproducts. This is concerning since 300 million individuals around the globe are users of smokeless tobacco. Significant evidence has shown that microbial metabolic activities mediate the formation of carcinogens during manufacturing. In recent years, studies have revealed a series of additional health impacts that include lesions and inflammation of the oral mucosa and the gastrointestinal tract, as well as alterations of the endogenous microbiota. These findings are due to recent developments in molecular technologies that allowed researchers to better examine the microbial component of these products. This new information illustrates the scale of the STP microbiota and its diversity in the finished product that is sold for consumption. Additionally, the application of metagenomics and metatranscriptomics has provided the tools to look at phylogenies across bacterial, viral, and eukaryotic groups, their functional capacities, and viability. Here we present key examples of tobacco microbiology research that utilizes newer approaches and strategies to define the microbial component of smokeless tobacco products. We also highlight challenges in these approaches, the knowledge gaps being filled, and those gaps that warrant further study. A better understanding of the microbiology of STP brings vast public health benefits. It will provide important information for the product consumer, impact manufacturing practices, and provide support for the development of attainable and more meaningful regulatory goals.Key points Newer technologies allowed quicker and more comprehensive identification of microbes in tobacco samples, encapsulating microorganisms difficult or impossible to culture. Current research in smokeless tobacco microbiology is filling knowledge gaps previously unfilled due to the lack of suitable approaches. The microbial ecology of smokeless tobacco presents a clearer picture of diversity and variability not considered before.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00253-021-11382-z.

Ultrasound-assisted dispersive microsolid-phase extraction approach for preconcentration of trace cobalt and nickel and sensitive determination in water, food and tobacco samples by flame atomic absorption spectrometry

ABSTRACT Simpleand validated ultrasound-assisted dispersive microsolid-phase extraction (UA-DMSPE) approach for separation, and preconcentration of trace cobalt (Co(II)) and nickel (Ni(II)) ions in various water, juice, food and tobacco samples prior to their flame atomic absorption spectrometry determination (FAAS) was developed. The proposed method based on using oxidized multiwalled carbon nanotubes (ox-MWCNTs) as adsorbent and 3-(2-hydroxy-5-acetylphen-1-ylazo)-1,2,4-triazole (HAPAT) as complexing agent at pH 7.0. The effect of different parameters has been investigated and optimised. The calibration curves were linear in the ranges of 1.0–300 and 2.0–400 μg L−1 and the limits of detection were 0.30 and 0.60 μg L−1 for Co(II) and Ni(II) ions, respectively, under the optimum conditions.The preconcentration factor was 200. Co(II) and Ni(II) havemaximum sorption capacities of around 300 and 370 mg g–1, respectively. The recovery rates of the analytes ranged from 96.0 to 101%. Furthermore, relative standard deviation (RSD%) for intra-day (1.40 and 1.90%) and inter-day (1.70 and 2.10%) as repeatability for Co(II) and Ni(II), respectively. Certified reference materials (SRM 1570A spinach leaves and TMDA-52.3 fortified water) were used to verify the accuracy of the proposed preconcentration protocol. The proposed method was successfully used to determine the content of Co(II) and Ni(II) ions in a variety of real water, juice, food and tobacco samples yielding satisfactory results.

Relationship between Free Amino Acid Index and Burnt-Mellow-Sweet Aroma Style Intensity of Flue-Cured Tobacco Leaves

80 samples of flue-cured tobacco leaves in Ganzhou area, Jiangxi Province in China were selected, relationships between free amino acid index and burntmellow- sweet aroma style intensity of leaves were studied with correlation analysis and stepwise regression analysis. In contrast to the content of Trp, Ile, Ser, Cys, β-Ala, Lys and the ratio of β-AiBA/TFAA, the content of Asp, Ala, Gly, Leu, β-AiBA and the ratio of Trp/TFAA, Ile/TFAA, Val/TFAA, Thr/TFAA, Ser/TFAA, Cys/TFAA, Asn/TFAA, β-Ala/TFAA, Lys/TFAA and Pro/TFAA in fluecured tobacco leaves had extremely significant positive correlation with burntmellow- sweet aroma style intensity. There was a significant negative correlation between burnt-mellow-sweet aroma style intensity and the content of Phe, Tyr, Asn, γ-ABA. 31 free amino acid indexes including the content of Asp, Glu, Phe etc. and the ratio of Glu/TFAA, Phe/TFAA, Trp/TFAA, etc. were main free amino acid index influencing burnt-mellow-sweet aroma style intensity of flue-cured tobacco leaves, which jointly decides 99.1% of variation of burnt-mellow-sweet aroma style intensity.

Auto-classification of biomass through characterization of their pyrolysis behaviors using thermogravimetric analysis with support vector machine algorithm: case study for tobacco

BackgroundDuring the biomass-to-bio-oil conversion process, many studies focus on studying the association between biomass and bio-products using near-infrared spectra (NIR) and chemical analysis methods. However, the characterization of biomass pyrolysis behaviors using thermogravimetric analysis (TGA) with support vector machine (SVM) algorithm has not been reported. In this study, tobacco was chosen as the object for biomass, because the cigarette smoke (including water, tar, and gases) released by tobacco pyrolysis reactions decides the sensory quality, which is similar to biomass as a renewable resource through the pyrolysis process.ResultsSVM algorithm has been employed to automatically classify the planting area and growing position of tobacco leaves using thermogravimetric analysis data as the information source for the first time. Eighty-eight single-grade tobacco samples belonging to four grades and eight categories were split into the training, validation, and blind testing sets. Our model showed excellent performances in both the training and validation set as well as in the blind test, with accuracy over 91.67%. Throughout the whole dataset of 88 samples, our model not only provides precise results on the planting area of tobacco leave, but also accurately distinguishes the major grades among the upper, lower, and middle positions. The error only occurs in the classification of subgrades of the middle position.ConclusionsFrom the case study of tobacco, our results validated the feasibility of using TGA with SVM algorithm as an objective and fast method for auto-classification of tobacco planting area and growing position. In view of the high similarity between tobacco and other biomasses in the compositions and pyrolysis behaviors, this new protocol, which couples the TGA data with SVM algorithm, can potentially be extrapolated to the auto-classification of other biomass types.

Aroma components of tobacco powder from different producing areas based on gas chromatography ion mobility spectrometry

Abstract Gas chromatography-ion mobility spectrum (GC-IMS) is used to analyze and compare the differences in aroma among different tobacco samples. The aroma substances in tobacco samples in Jilin Changchun are the richest, while those in Guangdong Nanxiong are the lowest. The concentrations of aroma substances such as decanal, 1-hydroxy-2-propanone, and 2-methylbutanol were the highest in Guangdong Nanxiong of the three. The concentration of 1-hexanol, cyclohexanone, pentanoic acid, and other aroma substances in Fujian Nanping was high. The concentration of 2-acetylfuran, 2-octanol, isopentanol, 3-methylvaleric acid, phenylacetic acid, and other aroma substances in Changchun area of Jilin Province was low. Through principal component analysis and similarity research, both tobaccos can be distinguished by their production areas and grades from the same.

Bazı tütün örneklerinde doğal radyonüklitlerin aktivite konsantrasyonları ve yıllık etkin doz değerleri üzerine bir çalışma

Tobacco samples were collected from different tobacco markets from Antalya in Turkey. To calculate natural radionuclides activity concentration, samples were counted for 86400 seconds by using high purity germanium (HPGe) detector. Activity concentrations of 226Ra, 232Th and 40K for tobacco samples found higher than minimum detectable activity (MDA). 137Cs was not detected in any sample. Activity concentration of 226Ra, 232Th and 40K range from 83±15 Bqkg-1 to 325±45 Bqkg-1, 29±5 Bqkg-1 to 207±37 Bqkg-1 and (2.09±0.28)x103 Bqkg-1 to (5.07±0.90) x103 Bqkg-1, respectively. In addition, annual effective dose value was calculated. The annual effective dose values owing to inhalation for adults change from 2.76 to 9.91 µSvy-1 for 214Pb, from 5.69 to 27.69 µSvy-1 for 214Bi, from 5.72 to 40.41 µSvy-1 for 228Ac, from 42.23 to 102.37 µSvy-1 for 40K. The total annual effective dose values change from 0.05 to 0.16 mSvy-1.

Biological control of Fusarium wilt of sesame by Penicillium bilaiae 47M-1

The purpose of the present study was to explore the control of Fusarium wilt of sesame caused by Fusarium oxysporum via Penicillium sp. 47M-1. Isolate 47M-1 was isolated from rhizosphere soil samples of tobacco and identified as Penicillium bilaiae based on morphological characteristics and ITS-rDNA, β-tubulin and calmodulin sequences. Isolate 47M-1 inhibited the mycelial growth of F. oxysporum by 81.3% and overgrew the colonies of F. oxysporum in co-cultures. In a potting test, the control efficiency of isolate 47M-1 against Fusarium wilt of sesame was 50%, which was superior to that of Bacillus subtilis (P = 0.022). There was no significant difference (P = 0.068) in the control of Fusarium wilt between treatment with the fungicide carbendazim and treatment with isolate 47M-1. The results also showed that isolate 47M-1 and its culture filtrate significantly promoted the growth of sesame. Quantitative real time-PCR detection showed that the response-related genes NPR1, Coi1, PR1, PR2 and PR3 were significantly upregulated under the combined stimulation of isolate 47M-1 and F. oxysporum compared to their expression under F. oxysporum treatment alone. In conclusion, isolate 47M-1 can control Fusarium wilt of sesame via multiple mechanisms, including competition, production of inhibitory substances, promotion of plant growth and induction of disease resistance.

Bioaccumulation of Cadmium in Nicotiana tabacum L. (Tobacco) Characterized by Soil Properties: A Case Study in the Sichuan Basin, China

The objective of this study was to determine the distribution of cadmium (Cd) accumulation in tobacco and identify the relationship between soil properties and plant Cd concentration. Forty soil and tobacco samples were collected from the Sichuan Basin, China (Panzhihua, Luzhou, Guangyuan and Yibin). The results showed the highest Cd in soil (2.94 mg kg−1) was in Yibin. Correspondingly, Cd concentrations in tobacco from Yibin were significantly higher than those from the other regions. The Cd concentrations in tobacco from Yibin, Luzhou, Guangyuan and Panzhihua were from 2.22 to 13.14, 0.59 to 2.12, 0.26 to 0.61, 0.10 to 0.37 mg kg−1, respectively. The Cd concentrations in leaves were higher than those in stems and roots. The highest Cd concentrations were in lower leaves, between 0.36 and 13.14 mg kg−1. In Yibin, the Cd in lower leaves nearly exceeded 10 mg kg−1 and the ratio of the Cd tobacco and soil concentrations (the bioconcentration factor, BCF) was 9.41. Path analysis showed soil pH and cation exchange capacity (CEC) were the most significant properties exhibiting direct effects on Cd accumulation. Stepwise multiple linear regression showed that soil Cd, pH, CEC and organic carbon (OC) were the major factors controlling Cd bioavailability to tobacco leaves, explaining more than 94.0% of the variance. The results are useful in predicting the transfer of Cd from soil to tobacco.

Analysis of Pyrolysis Characteristics and Kinetics of Cigar Tobacco and Flue-Cured Tobacco by TG-FTIR

Summary Investigation of the detailed pyrolysis characteristics of tobacco raw materials is important for the understanding of product design and consumption. In this work, pyrolysis characteristics and kinetic models of cigar filler tobacco (CFT), cigar wrapper tobacco (CWT), and flue-cured tobacco (FCT) were investigated by using a thermogravimetric analyzer coupled with Fourier-transform infrared spectroscopy (TG-FTIR). The pyrolysis of different tobacco samples could be divided into four stages based on the derivative thermogravimetric analysis (DTG) curves. Flue-cured tobacco underwent a marked decomposition process at lower temperatures (about 200 °C), while the thermal decomposition of cigar tobacco occurs at higher temperatures. During the pyrolysis process, evolved gases including H2O, CO2, CH4, CO, carbonyls, alcohols, phenols and aromatic compounds were detected by FTIR. CWT released more CO2 than CFT, while the amount of CO2, CH4, CO and aromatic compounds released by flue-cured tobacco was lower than that of cigar tobacco. The pyrolysis kinetics of tobacco leaves were further analyzed and compared through the isoconversional FWO (Flynn-Wall-Ozawa) and KAS (Kissinger-Akahira-Sunose) methods. The activation energy of FCT (from 100.1 kJ mol−1 to 192.1 kJ mol−1) was lower than that of CFT (from 207.36 kJ mol−1 to 319.28 kJ mol−1) and CWT (from 160.40 kJ mol−1 to 260.45 kJ mol−1). The thermal decomposition kinetics of different tobaccos were analyzed by Málek and Coats-Redfern methods.

Separation of N′-nitrosonornicotine isomers and enantiomers by supercritical fluid chromatography tandem mass spectrometry

N′-nitrosonornicotine (NNN) is one of the most prevalent and toxic tobacco-specific nitrosoamines. A chiral center at its 2′-position results in R and S enantiomers, the partial double bond character of the NN = O group also results in E and Z isomers, therefore, NNN can form a total of four absolute configurations (E-(R)-NNN, E-(S)-NNN, Z-(R)-NNN, and Z-(S)-NNN). This study investigated the resolution of R/S enantiomers and E/Z isomers of NNN by supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS). The baseline separation of E/Z-(R,S)-NNN isomers/enantiomers was accomplished through the optimization of chiral columns and co-solvents. Due to the lack of single standard of E/Z isomers, only R-NNN (sum of E-(R)-NNN and Z-(R)-NNN) and S-NNN (sum of E-(S)-NNN and Z-(S)-NNN) were further examined. Through the comprehensive optimization of SFC-MS/MS conditions, R-NNN and S-NNN were separated with a run time of 5 min, the developed method was validated, and its applicability to the determination of NNN enantiomers in burley tobacco samples was demonstrated. This study could be applied to preparative separation of single enantiomer and/or isomer of NNN, and could provide potential benefits to biologic activity studies on these enantiomers and isomers.

Computer simulation assisted preparation and application of myclobutanil imprinted nanoparticles

In this paper, computer simulation was used to assist in the rapid preparation of Myclobutanil (MYC) molecularly imprinted nanoparticles (MYC-MINs), which involved screening the best functional monomers and solvents, determining the optimal polymerization ratio, and estimating the MYC-2-(Trifluoromethyl)acrylic acid (MYC-TFMAA) self-assembly process and its infrared spectrum. Thermodynamic analysis showed that MYC-TFMAA self-assembly was an endothermic non-spontaneous process, and the pre-polymerization temperature was planned to be 30 °C. The MYC-MINs, prepared by solution polymerization, had a uniform particle size (the average diameter of 134.26 nm, pore volume of 2.45 mL/g, specific surface area of 143.26 m2/g, and porosity of 78.27%). The polymer got to its dynamic adsorption equilibrium in 90min, and the saturated adsorption capacity was 4.78 mg/g. Repeated adsorption experiments proved that the MYC-MINs had stable physical and chemical properties, and a high specific adsorption capacity for MYC and its structural analogs as well. The separation imprinting factors of the polymer for MYC could reach to 2.31, and it was used as a filler in the solid phase extraction tube to purify the tobacco samples spiked with six triazole fungicide, and finally the extracts were analyzed by UHPLC-MS/MS. The average recovery range of spiked tobacco samples were 77.86%–100.52%, and relative standard deviation was 1.90%–10.60% (n = 3), which realized simultaneous detection of multiple triazole fungicides in tobacco.

An Eco-Friendly Ultrasound-Assisted Emulsification Dispersive Liquid–Liquid Microextraction of Nickel in Environmental Samples Coupled with Spectrophotometry

A new, simple, rapid, sensitive and environmentally friendly ultrasound-assisted emulsification dispersive liquid–liquid microextraction (UAE-DLLME) has been developed for trace nickel Ni(II) separation and preconcentration in environmental samples prior to spectrophotometric determination. The proposed method based on using non-ionic water-soluble surfactant Triton X-114 (TX-114) as a disperser solvent and tetrachloroethylene as an extractive solvent. A 6-(1,3-thiazolylazo)-2-nitrophenol (TANP) as complexing agent was used for complexation of Ni(II) at pH 7.0. The influence of various variables on the performance of the UAE-DLLME method was optimized. Under the optimal conditions, the calibration graph was linear in the rage of 1.0-300 μg L-1. The detection and quantitation limits of the method were determined as 0.3 and 1.0 μg L-1, respectively. The preconcentration factor and enhancement factor were obtained as 60 and 45. Relative standard deviation (RSD %) as precision at 100 and 200 µg L-1 of Ni(II) were 1.4 and 2.1%, respectively (n=10). The validation of the developed method was proved by analysis of certified reference materials. Finally, the developed UAE-DLLME microextraction method was applied to preconcentrate and determine of trace levels of Ni(II) in real water, food and tobacco samples with satisfactory results.