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Liu L.,Central China Normal University | Zuo M.,Central China Normal University | Zuo M.,Enshi Prefecture Tobacco Company | Cheng J.,Central China Normal University | And 3 more authors.
Microchimica Acta | Year: 2011

A sensitive method has been established for the determination of the pyrethroids (fenpropathrin and permethrin) in water samples. It is based on microextraction using monoliths composed of a poly-(glycidyl methacrylate-co-ethylene dimethacrylate) copolymer, and on detection by gas chromatography coupled to electron-capture detection. Experimental parameters including the flow rate and volume of the samples, the type, volume and flow rate of eluent and effect of salt addition were optimized. The limits of detection for fenpropathrin and permethrin are 0.5 and 2.7 ng mL-1, respectively. The intra-day and inter-day precisions were less than 5.5% and 9.0%. The method was successfully applied to determination of two pyrethroids in the tap and lake water samples and the accuracy was evaluated by recovery experiments. © 2011 Springer-Verlag. Source

Zuo M.,Enshi Prefecture Tobacco Company | Cheng J.,Central China Normal University | Matsadiq G.,Central China Normal University | Liu L.,Central China Normal University | And 2 more authors.
Clean - Soil, Air, Water | Year: 2012

Dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) technique was successfully applied for simultaneous assay of eight polychlorinated biphenyls, two organochlorine, and four pyrethroid pesticides multi-residue in aqueous samples by using GC-electron capture detection. The effects of various parameters such as kind of extractant and dispersant and volume of them, extraction time, effect of salt addition, and pH were optimized. As a result, 5.0μL 1-dodecanol was chosen as extraction solvent, 600μL methanol were used as dispersive solvent without salt addition, pH was adjusted to 7. Under the optimized conditions, the limits of detection (LOD) were ranged from 1.4 to 8.3ngL-1. Satisfactory linear range was observed from 5.0 to 2000ngL-1 with correlation coefficient better than 0.9909. Good precisions were also acquired with RSD better than 13.6% for all target analytes. The enrichment factors of the method were ranged from 786 to 1427. The method can be successfully applied to simultaneous separation and determination of three class residues in real water samples and good recoveries were obtained ranging from 76 to 130, 73 to 129, and 78 to 130% for tap water, lake water, and industrial waste water, respectively. DLLME-SFO coupling with GC-ECD can be successfully applied to pre-concentration, separation, and detection of low levels of organic pollutant residues in environmental aqueous samples. The proposed method is simple, fast, accurate, inexpensive, and possesses great potential for the simultaneous determination of multi-residues with similar polarity at a low concentration levels. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Li M.,Enshi Prefecture Tobacco Company | Zhu J.,Enshi Prefecture Tobacco Company | Ding C.,Enshi Prefecture Tobacco Company | Zhu Z.,Enshi Prefecture Tobacco Company | Cai Z.,Enshi Prefecture Tobacco Company
Acta Tabacaria Sinica | Year: 2013

Structure of labour power, cost-benefit, willingness to grow were surveyed and analyzed in three successive years to determine main factors affect tobacco agriculture development. Results showed that: unbalanced personnel structure, natural disaster, labor-intensive, production inputs, low comparative effectiveness, low mechanization level and professional service level are important factors that affect Enshi tobacco economy development. Suggestions were put forward to promote stability development in tobacco leaf production, such as stabilize professional farmer's team, strengthen management of production technician, enhance technology innovation and popularize appropriate technology. Source

Di H.,Enshi Prefecture Tobacco Company | Guo Y.,Enshi Prefecture Tobacco Company | Li P.,Enshi Prefecture Tobacco Company | Cai Z.,Enshi Prefecture Tobacco Company | And 3 more authors.
Acta Tabacaria Sinica | Year: 2014

Pot experiments were conducted to study amelioration effect of meerschaum in Cd contaminated tobacco soil through simulation. Results showed that meerschaum can effectively improved soil pH value, reduce Cd activity and refrain tobacco plant from absorbing Cd. It resulted in less total sugar and reducing sugar and more total nitrogen, nicotine, potassium and chlorine. It is concluded that soil acidic environment can be ameliorated if added with 30%~40% meerschaum, thus improving tobacco safety and productivity. ©, 2014, State Tobacco Monopoly Bureau and China Tobacco Society. All right reserved. Source

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