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161.
In this work, water and sediment samples were collected from three different stations located along the Sakarya river between May and September 2003. Lead, copper, chromium, zinc, nickel and cadmium concentrations were determined by using solvent extraction and flame atomic absorption spectrometric method. The results show that differences based upon sampling times, regions, sediment and water samples were observed. The mean levels of copper, nickel, chromium, lead, cadmium, zinc for sediment samples are; 4.630 μg g−1, 13.520 μg g−1, 8.780 μg g−1, 2.550 μg g−1, 9.990 μg g−1 and for water samples are; 0.851 μg g−1, 1.050 μg g−1, 0.027 μg g−1, 1.786 μg g−1, 0.236 μg g−1, 0.173 μg g−1, respectively.  相似文献   
162.
The activity concentrations of soil samples collected from thirty different locations of Malwa region of Punjab were determined by using HPGe detector based on high-resolution gamma spectrometry system. The range of activity concentrations of 226Ra, 232Th and 40K in the soil from the studied areas varies from 18.37 Bq kg−1 (Sangrur) to 53.11 Bq kg−1 (Sitoguno), 57.28 Bq kg−1 (Dhanola) to 148.28 Bq kg−1 (Sitoguno) and 211.13 Bq kg−1 (Sunam) to 413.27 Bq kg−1 (Virk Khera) with overall mean values of 35 Bq kg−1, 80 Bq kg−1and 317 Bq kg−1 respectively. The absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranges between 8.47 and 24.48, 35.68 and 92.38, and 8.74 and 17.11 nGy h−1, respectively. The total absorbed dose in the study area ranges from 58.08 nGy h−1 to 130.85 nGy h−1 with an average value of 79.11 nGy h−1. The calculated values of external hazard index (Hex) for the soil samples of the study area range from 0.35 to 0.79. Since these values are lower than unity, therefore, according to the Radiation Protection 112 (European Commission. Radiation Protection 112 1999) report, soil from these regions is safe and can be used as a construction material without posing any significant radiological threat to population.  相似文献   
163.
Cadmium and lead were determined simultaneously in seawater by differential pulse stripping voltammetry (DPSV) preceded by adsoptive collection of complexes with 8-hydroxyquinoline (oxine) on to a hanging mercury drop electrode (HMDE). In preliminary experiments the optimal analytical condition for oxine concentration was found to be 2.10−5 M, at pH 7.7, the accumulation potential was −1.1 V, and the initial scannig potential was −0.8 V. The peak potentials were found −0.652 V for Cd and −0.463 V for Pb At the 60 s accumalation time. The limit of detection (LOD) and limit of quantitatification (LOQ) were found to be by voltammetry as 0.588 and 1.959 μg l−1 (RSD, 5.50%) for Cd and 0.931 and 3.104 μg l−1 (RSD, 4.10%) for Pb at 60 s stirred accumulation time respectively. In these conditions the most of the seawater samples are amenable for direct voltammetric determination of cadmium and lead using a HMDE. An adsorptive stripping mechanism of the electrode reaction was proposed. For the comparison, seawater samples were also analysed by ICP-atomic emission spectrometry method (ICP-AES). The applied voltammetric technique was validated and good recoveries were obtained.  相似文献   
164.
长江沉积物中痕量氯代酚类化合物的测定   总被引:12,自引:0,他引:12  
本文利用同位素稀释质谱法对长江南京段沉积物中18种氯代酚进行了分离鉴定,结果表明,沉积物中CPs的含量以五氯苯酚为主,  相似文献   
165.
建立了土壤和沉积物中8种多溴联苯醚(PBDEs,BDE-28、BDE-47、BDE-99、BDE-100、BDE-153、BDE-154、BDE-183和BDE-209)加速溶剂同时萃取和净化-气相色谱-三重四极杆串联质谱(ASE-GC-MS-MS)的分析方法。通过优化加速溶剂萃取与弗罗里硅土在线净化和串联质谱多反应监测模式的条件,较好地去除基质干扰,并提高了三重四极杆串联质谱定性的准确性及定量的灵敏性。该方法采用改进的色谱柱能同时分析包括高溴代联苯醚BDE-209在内的8种PBDEs,其浓度范围为1~100 ng/mL(BDE-209为10~1 000 ng/mL),线性良好,线性回归系数均大于0.997。方法检出限为0.004~0.1 ng/g,方法回收率为75%~110%,方法精密度为2.4%~15.6%。适于批量处理土壤和沉积物中含有多组分痕量PBDEs的样品。  相似文献   
166.
建立了固相萃取-超高效液相-串联质谱法同时测定水环境中26种类固醇激素的分析方法。明确了取样体积为500 m L,Cleanert PEP为富集柱,乙酸乙酯为洗脱剂,甲醇为溶剂进行提取操作。选择了正离子模式,以0. 1%甲酸/甲醇-水为流动相,负离子模式以0. 1%氨水/乙腈-水为流动相,试样经AcquityTMUPLC BEH C18色谱柱分离后,选用质谱检测模式进行定性、定量分析。通过方法验证,26种类固醇激素的方法检出限为0. 3~1. 5 ng/L,测定下限为1. 2~6. 0 ng/L,代表性样品测定结果的相对标准偏差为2. 6%~13. 7%(n=6),加标回收率为71. 2%~121%。该方法操作便捷,灵敏度高,精密度和准确度良好,可适用于水环境中多种痕量、超痕量类固醇激素的定性定量分析。  相似文献   
167.
基于气相色谱-质谱联用(GC-MS)法结合固相萃取(SPE)前处理技术,建立了水中4种除草剂氯草定、阿特拉津、乙草胺和异丙甲草胺残留的分析方法,于2018年春(4、5月)、秋(9、10月)和冬(1、3月)季对太湖流域望虞河西岸九里河水体中4种除草剂的污染现状进行调查分析。结果表明,4种除草剂的加标回收率为71. 2%~108%,RSD均10%,方法检出限为3. 5~6. 0 ng/L。九里河水体中氯草定、阿特拉津、乙草胺和异丙甲草胺4种除草剂质量浓度分别为未检出~0. 025 7,0. 019 1~1. 19,未检出~0. 026 0和未检出~0. 094 3μg/L。4种除草剂中阿特拉津最高值接近《地表水环境质量标准》(GB 3838—2002)限值,其他3种其值较低,氯草定首次在太湖流域水体中检出。  相似文献   
168.
The free living nematode Caenorhabditis elegans is a proven model organism for lipid metabolism research. Total lipids of C. elegans were extracted using chloroform and methanol in 2:1 ratio (v/v). Fatty acids composition of the extracted total lipids was converted to their corresponding fatty acids methyl esters (FAMEs) and analyzed by gas chromatography/accurate mass quadrupole time of flight mass spectrometry using both electron ionization and chemical ionization techniques. Twenty-eight fatty acids consisting of 12 to 22 carbon atoms were identified, 65% of them were unsaturated. Fatty acids containing 12 to17 carbons were mostly saturated with stearic acid (18:0) as the major constituent. Several branched-chain fatty acids were identified. Methyl-14-methylhexadecanoate (iso- 17:0) was the major identified branched fatty acid. This is the first report to detect the intact molecular parent ions of the identified fatty acids in C. elegans using chemical ionization compared to electron ionization which produced fragmentations of the FAMEs.  相似文献   
169.
The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm?3 and 0.05–5.753 μgm?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd?1 for exposure of the public and as 274 ngd?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics.  相似文献   
170.
为了解15种药物及个人护理用品(PPCPs)在中小型污水处理厂中的分布及其去除效果,采用液相色谱-串联质谱(LC-MS/MS)技术对3座A2/O工艺的污水处理厂水样进行分析研究。结果显示,除普萘洛尔、吉非罗平和吲哚美辛在3座中小型污水处理厂各个工艺单元中均未被检出外,其余12种目标化合物的检出频率在90%~100%之间。进水水样中PPCPs的平均检出浓度为2 285.4 ng/L,其中咖啡因(CF)的平均检出浓度最高为973.3 ng/L,酮洛芬(KP)的平均检出浓度次之为844.7 ng/L,两者之和占进水水样中PPCPs平均含量的79.5%,表明污水处理厂的主要污染物为CF和KP。3座污水处理厂对CF的去除效果最为显著,平均去除率为95.3%,对15种PPCPs总去除效率在39.3%~82.8%之间。  相似文献   
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