Wang X.-B.,Jiangxi Agricultural University |
Wu R.-M.,Jiangxi Agricultural University |
Ling J.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
Liu M.-H.,Jiangxi Agricultural University |
And 3 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2016
Surface enhanced Raman spectroscopy (SERS) and quick pre-treatment technology were used to detect triazophos residues in flesh of navel orange. Quantitative analysis model was developed by partial least squares (PLS) algorithm. SERS of different concentration (0.5 to 20 mg·L-1) triazophos juice solution with flesh extract as the matrix were collected by laser Raman spectrometer. Three preprocessing methods such as normalization, MSC and SNV were used to optimize Raman signals and PLS models were set up. The results showed that minimum detection concentration for triazophos in navel orange below 0.5 mg·L-1. The model built with normalization pre-processing gave the best result; the values of correlation (Rp) and Root mean square error of prediction set (RMSEP) were 1.38 and 0.976 6, respectively. The predict recoveries were 95.97%~103.18% and the absolute values of relative errors were below 5%. T-test (t=-0.018) showed that there was no significant difference between the true values and prediction values. This study demonstrates that this method is accurate and reliable. © 2016, Peking University Press. All right reserved.
Wang L.,China Agricultural University |
Gao L.,China Agricultural University |
Shen Z.,China Agricultural University |
Huang L.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
Qian X.,Beijing Information Science and Technology University
Proceedings - 2011 7th International Conference on Natural Computation, ICNC 2011 | Year: 2011
Application of mathematical morphology has speeded up into identification of species, including insects. In this study, we use TpsDig, a software product for feature extraction, to locate 17 landmarks with their coordinate value on digital images of wing samples from four species of fruit fly (Bactrocera dorsalis, B. cucurbitae, B. tau, B. scutellata) in Tephritidae. Twenty two geometrical morphometric parameters are evaluated to analyse the morphological divergence among the four species. Three standardized canonical discriminant functions are formulated: Y 1=0.114X 1+1.121X 2+0.613X 3-0.067X 40.019X 5, Y 2=0.515X 1-0.001X 2+1.379X 3-2. 242X 4-0.795X 5, and Y 3=0.962X 1+0.071X 2+0.589X 3+0.091X 4-0. 780X 5. It proves that correctness of the samples in species identification can reach at 98.1%. © 2011 IEEE.
Simultaneous determination of organophosphorus, organochlorine, pyrethriod and carbamate pesticides in Radix astragali by microwave-assisted extraction/dispersive-solid phase extraction coupled with GC-MS
Mao X.,Nanchang University |
Wan Y.,Nanchang University |
Yan A.,Nanchang University |
Shen M.,Nanchang University |
Wei Y.,Jiangxi Entry Exit Inspection and Quarantine Bureau
Talanta | Year: 2012
A simple, rapid and reliable method was proposed for the simultaneous determination of 27 pesticides (organophosphorus, organochlorine, pyrethroid and carbamate pesticides) in Radix astragali. The pesticides were extracted by acetonitrile and the experimental variables, such as temperature, extraction time and volume of acetonitrile, were optimized through orthogonal array experimental design. Cleanup of extracts was performed with dispersive-solid phase extraction using primary secondary amine (PSA) as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS, SIM). The linearity of the calibration curves is good in matrix-matched standard, and yields the coefficients of determination (R2)≥0.99 for approximately 96% of the target analytes. Under optimized conditions, the average recoveries (six replicates) for most pesticides (spiked at 0.02, 0.1 and 0.2 mg kg-1) range from 70% to 120%, and RSDs are less than 17.2%. © 2012 Elsevier B.V. All rights reserved.
Hu M.-L.,Nanchang University |
Zhou H.-M.,Jiangxi Fisheries Research Institute |
Li F.,Jiangxi Entry Exit Inspection and Quarantine Bureau
Hydraulic Engineering - Proceedings of the 2012 SREE Conference on Hydraulic Engineering, CHE 2012 and 2nd SREE Workshop on Environment and Safety Engineering, WESE 2012 | Year: 2013
Spatiotemporal variation of Chlorophyll a (Chla) concentration and its relationship with other water quality factors in the Poyang Lake outlet were analyzed during the period of 2007 to 2008. The results indicated that the Chla concentration was 4.46 ±1.53 mg · m-3 in 2007 and 4.60 ±1.67 mg · m-3 in 2008. Additionally, the Chla concentration reached a peak in August or September while bottomed out in January or December. And its values were significantly higher in the left sampling site than that in the middle and right sampling sites. Moreover, the Chla concentration in Poyang Lake outlet showed significant positive correlation with Z, WT, SD while SS, DO, COD and nutrients were inversely related. But no obvious correlation was found between pH and Chla in Poyang Lake outlet. The study would highlight further research needs for the distribution patterns of chlorophyll a in association with hydrological features in Poyang Lake. © 2013 Taylor & Francis Group.
Zuo H.G.,Nanjing Agricultural University |
Zhu J.X.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
Zhan C.R.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
Shi L.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
And 4 more authors.
Environmental Monitoring and Assessment | Year: 2015
Malathion is an organophosphorous insecticide for controlling insects on fruits and vegetables, miscellaneous household insects, and animal parasites. It is important to develop highly efficient and selective pre-treatment method for analyzing malathion residues in environment and samples from agricultural products based on the molecularly imprinted polymers (MIPs). In this study, we developed a tailor-made MIP method with highly specific recognization to the template. The MIPs were prepared using malathion as a template, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, azodiisobutyronitrile (AIBN) as an initiator, and the acetonitrile-chloroform (1:1, v/v) as a porogen. The molecular recognization mechanism of malathion and MAA was evaluated by molecular simulation, ultraviolet spectrometry (UV), and 1H-nuclear magnetic resonance (1H-NMR). MAA interacted specifically with malathion by hydrogen bond with a ratio of 2:1. The MIPs exhibit a high affinity, recognition specificity, and efficient adsorption performance for malathion. The Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), surface area and porosimeter analyzer, thermogravimetric/differential thermal analyzer (TG/DTA) were used to characterize the properties of MIP. The malathion residues in soil, tap water, and cabbage were cleaned up by MIP-SPE, detected quantitatively using GC-FPD, and confirmed by GC-MS/MS. The limits of tap water, soil, and cabbage were confined to 0.001 mg L−1, 0.004 and 0.004 mg kg−1, respectively. The spiked recoveries of malathion were 96.06–111.49 % (with RSD being 5.7–9.2 %), 98.13–103.83 % (RSD, 3.5–8.7 %), and 84.94–93.69 % (RSD, 4.7–5.8 %) for tap water, soil, and cabbage samples, respectively. Thus, the method developed here can be used effectively in assessing malathion residues in multiple environmental samples. The aim of the study was to provide an efficient, selective, and accurate method for analyzing malathion at trace levels in multiple media. © 2015, Springer International Publishing Switzerland.
Zhang J.,Shanghai Entry Exit Inspection and Quarantine Bureau |
Wei Y.,Shanghai Entry Exit Inspection and Quarantine Bureau |
Chen J.,Shanghai Entry Exit Inspection and Quarantine Bureau |
Wang W.,Shanghai Entry Exit Inspection and Quarantine Bureau |
Shi L.,Jiangxi Entry Exit Inspection and Quarantine Bureau
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2013
The contents of benzene and organic oxygenates in gasoline were determined by two-dimensional gas chromatography with a heart-cutting system. The retention time of common organic oxygenates and benzene in gasoline were confirmed both when column switched and non-switched, and a new dual-column qualitative and quantitative analysis method was established. The system performance is more reliable as both the dead volume and the baseline fluctuation were smaller, and the repeatability of the retention time was better. Through qualitative and quantitative analysis of the samples and the recovery rate and verification tests, this method was proofed to meet the technical requirements of EN 13132 and EN 12177 with good repeatability and high recovery, which can be used to determine the organic oxygenates and benzene in gasoline.
Zhang H.,Huaiyin Institute of Technology |
Yao W.,Jiangxi Entry Exit Inspection and Quarantine Bureau |
Chen Y.,Huaiyin Institute of Technology |
He P.,Huaiyin Institute of Technology |
And 3 more authors.
Natural Product Communications | Year: 2012
A simple and reliable HPLC method was developed and validated for the simultaneous quantification of four major constituents in Semen Vaccariae. The chromatographic separation was performed on an Agilent Zorbax SB-C18 column with gradient elution using methanol and water. The calibration curves showed good linearity of R2 > 0.9999 with LOQs (S/N = 10) of 0.20-1.16 μg/mL. The precision was evaluated by intra- and inter-day assays and R.S.D. values were less than 2.09%. The recovery rates were between 97.0% and 105.0%. The developed method was applied to the quantitative analysis of Semen Vaccariae and its stir-fried products. During the stir-frying process, vaccarin degraded and yielded isovitexin-2″-O-arabinoside. The preferable stir-frying temperature is around 120°C. The developed HPLC method can be applied to the quality control of crude and stir-fried Semen Vaccariae.
Chen L.,University of Sichuan |
Hu J.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Zhang W.,University of Sichuan |
Zhang J.,University of Sichuan |
And 3 more authors.
Food Analytical Methods | Year: 2015
A high-performance capillary electrophoresis (HPCE) method for simultaneous determination of nine banned azo dyes including orange 2 sodium salt, ponceau SX, ponceau 2R, metanil yellow, yellow 2G, ponceau 3R, naphthol orange, acid violet 7, and acid yellow 11 in foodstuffs and beverages was established. After being extracted with methanol and cleaned up with Proelut PWA column, the separation of the target azo dyes in sample solution was performed in an uncoated fused-silica capillary (60 cm × 75 μm I.D.) with an effective length of 50 cm. The running buffer consisted of 15 % acetonitrile-10-mM borate buffer (pH = 9.0), and the applied voltage was 25 kV with the separation temperature of 25 °C. The calibration curves of the method were linear in the range of 0.50–100.0 μg/ml with correlation coefficients greater than 0.999. The recoveries of the method ranged from 81.2 to 110 %. The limits of detection (LODs) and the quantification of the method were in the ranges of 25.1–75.1 μg/l and 0.083–0.25 mg/kg, respectively. The relative standard deviations (RSDs) of interday and intraday were in the ranges of 1.90 to 5.81 % and 0.12 to 3.42 %, respectively. This method has been successfully applied to the simultaneous determination of aforementioned nine azo dyes in foodstuffs and beverages. © 2014, Springer Science+Business Media New York.