Advanced Materials Research Vols. 726-731

Abstract: This work describes a routine monitoring method for simultaneous determination of three classes of veterinary antibiotics (quinolones, sulfonamides, and tetracylines) in the aquaculture water. The selected eleven pharmaceuticals include four quinolones (enoxacin, ofloxacin, ciprofloxacin and lomefloxacin), four sulfonamides (sulfadiazine, sulfadimidine, sulfamethoxazole and sulfisoxazole) and three tetracyclines (tetracycline, chlortetracycline, and doxycycline). The entire procedures for pre-concentration by solid phase extraction (SPE) using Oasis HLB, and liquid chromatography-ultraviolet spectrometry (LC-UV) quantification were examined and optimized. The chromatographic separations were performed on a Kromasil 100-C₁₈ (250 mm×4.6 mm, 5 μm) column, using 0.1% (v/v) formic acid in water and acetonitrile as mobile phase with gradient elution, and 280 nm as the detective wavelength. The recovery efficiencies were found to be 85-117% for quinolones, 81-109% for sulfonamides, and 84-110% for tetracyclines at three spiking levels (5, 10 and 50 μg/L). The developed method was applied to real water samples collected from four aquafarms located in Yichang, Hubei Province, China. Three or four tested antibiotics were detected in all water samples, with concentrations ranging from 0.65 μg/L to 4.33 μg/L. The method is convenient and rapid, and provides a quantitative measurement of multi-residue antibiotics without complex and expensive analytical equipment.

Abstract: Analysis on the variation characteristics of the air quality in Chongqing during the spring festivals from 2001 to 2013, and the weather-affecting system of the typical sample. The result shows that: Prior to and after the ban-lifting for the firecrackers setting in 2006, significant differences had shown in the API Index from the lunar New Years Eve to Jan.1. After an analysis on the large-scale circulation background during the spring festival of 2006 and 2008 with the meteorological observation data.The result shows that the air pollution during the spring festival is co-resulted from the pollution source of firecrackers setting and the meteorological system that is unsuitable for the pollutant diffusion.

Abstract: Analyze the air pollution index (API) variation characteristics in Chongqing, and the relationship between API and meteorological elements. Found that air quality of Chongqing is basically at level II. Primary pollutant is inhalable particle (PM10). Summer is the season with best air quality, while winter is the most polluted season. Visibility, precipitation, sunshine and other meteorological elements have a great effect on the variation of air quality. The correlation between air pollution index and visibility is the most significant, which is-0.37. However, inter-monthly variation of monthly total rainfall, monthly total sunshine duration and API shows obvious reverse phase variation.

Abstract: Microcystis aeruginosa is common in freshwater lakes, and developed easy. Instead of chlorophyll standard substance, fresh chlorophyll extraction from Microcystis aeruginosa applied to the determination of chlorophyll-a in water by fluorophotometry. Thus the relationship between concentration of chlorophyll-a and fluorescence intensity of Microcystis aeruginosa in water was established. The fluorescence intensity responded with the concentration of chlorophyll-a extract linearly in the range of 30~1800 ug/L with a correlative coefficient of 0.9947. Comparision was made between chlorophyll standard and the chlorophyll-a extraction of Microcystis aeruginosa, and no significant difference was found. In certain range of pH value and time, chlorophyll-a extraction from Microcystis aeruginosa is stable, and can be used to reflect the growth of algae in water quick, conveniently and accurately.

Abstract: A method for the simultaneous determination of organochlorine pesticide and pyrethroids in tea was established by gas chromatography equipped with electronic capture detector (GC-ECD).The organochlorine and pyrethroids in tea were extracted by acetonitrile, then filtered and concentrated organic phase, and separated and purified through a florisil column, then concentrated again and diluted with hexane to scale. The organochlorine pesticide and pyrethroids were analyzed by GC-ECD and qualified with external standard method. Experiments show that seven kinds of agricultural chemicals’ peak time range from 16.362 to 32.010 min, correlation coefficient in the range of 0.9992-0.9999, with excellent linearity. The lowest examination limits range from 0.018 mg/kg to 0.099 mg/kg and the recoveries between74.5% and 116% with relative standard deviations(RSD) of 1.4%-8.7%. The results showed that proposed method could used to determine these two kinds of pesticides in tea.

Abstract: A rapid and sensitive competitive immunochromatographic assay for aflatoxin B₁ (AFB₁) based on colloidal gold-antibody probe was developed. The limit of detection for AFB1 standard solution was 0.5ng/ml and for foodstuff sample was 10μg/Kg. Other aflatoxins including AFM₁, AFB₂, AFG₁, and AFG₂ have less cross-reactivity to the strip. The storge life of the strip was at least 12 monthes. The method was well agreement with the ELISA method by testing food samples. This method is suitable for rapid testing of AFB₁ on site.

Abstract: A highly sensitive chemiluminescence enzyme immunoassay (CLEIA) method for the determination of bisphenol A (BPA) was developed, which used a secondary antibody labeled with horseradish peroxidase detected with a luminol-based substrate. Under the optimized conditions, the linear range was 0.01μg/mL~0.74μg/mL, and the detection limit was 0.008μg/mL. The average recovery for BPA in barreled water was 104%. This developed method could be applied for the selective, high-throughput, and rapid determination of BPA in barreled water.

Abstract: Organic materials in soils mainly consist of alkanes, esters, aromatic compounds and plant secondary metabolites, but they are different from one another in material type and quantity, depending on the types of slopes. This paper conducts a comparitive study on soils from slopes along the Suining-Chongqing Railway. Preparing soil samples from the rocky slope, the cultivated and uncultivated slopes by using ultrasonic methods, we measured the organic materials with a chromatograph mass spectrometer (QP2100). The results show that the number and types of organic materials decrease from the cultivated slopes to uncultivated slopes and then to rocky slopes. No contaminant appears in artificial soils on rocky slopes, but it is found in natural soils. Hence, it can be concluded that the reconstruction of soils on engineering slopes is beneficial not only for ecological restoration, but also for the prevention of pollution.

Abstract: Focused on heavy pollution monitoring while ignoring ecological environmental destruction, existing environmental monitoring program also had disadvantages of unreasonable monitoring frequency setting. In order to be more scientific and reasonable, optimization design of environmental monitoring program was carried out in this paper under the principles of key monitoring by stages and modification of monitoring frequency according to the characteristics of construction process.

Abstract: The paper use the observational data of Chongqing from 1981to 2010, to analyze the spatial and the temporal distribution characters. The results are the follows: (1) Chongqing has two Foggy areas, one is the north by central region with Changshou, Fuling as the center, the other is the northwest region with Hechuan, Beibei as the center. (2) The fog mainly occurs in winter, and especially often occurs in December. (3)The number of the fog days are reduces in most Chongqing areas from 1990s to 2000s. Based on the NCEP reanalysis data, the paper analyze a fog weather, the results indicate that the wind by north at 500 hpa, the anticyclonic circulation at 700 hpa, the precipitation a few days ago, the high humidity at the lower layers and low humidity at higher layers cause the fog in November 7, 2006.