加压流体萃取-气相色谱质谱法测定土壤和沉积物中27种拟除虫菊酯类农药

建立了加压流体萃取-气相色谱质谱法测定土壤和沉积物中27种拟除虫菊酯类农药的方法。以丙酮/正己烷(V∶V=1∶1)为萃取溶剂,在120℃和10. 3 MPa条件下静态萃取7 min,循环3次,石墨化炭黑串接氨丙基键合硅胶固相萃取柱净化,HP-5MS UI色谱柱分离,优化了提取和分析过程的重要条件。方法检出限为0. 001~0. 012 mg/kg,土壤中低、高浓度的加标回收率范围分别为68. 3%~123%和75. 3%~115%,沉积物中低、高浓度的加标回收率范围分别为67. 1%~120%和78. 6%~110%,单一目标物的相对标准偏差(RSD)均<20%(n=6)。实验结果表明,该方法消耗溶剂少、效率高、检出限低、精密度和准确度好,适用于土壤和沉积物中拟除虫菊酯类农药残留的测定。     

调整已有地震动拟和规范反应谱人造地震动方法比较

利用已有的地震记录调整得到拟和规范反应谱的人造地震动的方法越来越得到广泛的认可和应用。常用的方法包括比较粗略的比例调整法、比较精确的调整傅里叶幅值谱法、基于小波变换的调整方法和时域内叠加小波函数的方法等。本文详细介绍了各种谱拟和方法的原理以及实现过程中的难点;通过算例分析,对各种方法的优缺点进行了探讨。结果表明:当已有地震动反应谱与规范反应谱相差较大时,可先采用比例调整法粗调,然后再采用其他三种比较精确的方法继续进行调整;后三种方法都能快速地由实际地震动时程纪录得到拟和规范反应谱的人造地震动时程,并一定程度上保留原始时程的非平稳特征;相比之下,时域内叠加小波函数的方法精度最高,调整完后不用进行基线调整,是一种值得推荐的方法。     

贵州黔东南州三板溪水库春季拟多甲藻水华特征

2011年3月13日对贵州省黔东南州三板溪水库进行春季浮游植物调查的结果表明,三板溪水库Ⅱ号采样点(下革东)发生以佩纳形拟多甲藻为优势种的拟多甲藻水华,细胞密度高达1.15×10⁷cell/L;板溪水库总氮的最低值为2.09 mg/L,总磷的最低值为0.95 mg/L,三板溪水库的总氮、总磷含量较丰富,不存在总氮或总磷是限制性因子;通过SPSS16.0统计软件分别进行Pearson 积距相关系数分析表明,氮磷比是三板溪水库发生拟多甲藻水华的主要影响原因。     

直接竞争ELISA检测拟柱孢藻毒素的方法建立和评价

拟柱孢藻毒素(CYN)对人和动物具有高毒性而在世界上广受关注,快速检测方法的建立可为蓝藻毒素的风险评估提供有效的技术手段.本研究基于前期制备的CYN的单克隆抗体N8,旨在建立一种CYN的快速免疫检测方法-直接竞争ELISA.在对HRP-CYN酶标记物和N8单抗的稀释度进行优化后,最适反应条件下建立的直接竞争ELISA在0～200ng/mL CYN浓度下呈现典型的S型反应曲线,该方法的灵敏度为0.069ng/mL,经logit-log拟合的线性范围为0.1～10ng/mL,检出限远低于WHO建议的0.7ng/mL CYN的安全限值.本研究建立的ELISA方法对水库水样和小球藻稀释液中加标回收率分别为80.44%～125.4%和52.97%～155.19%,在测定CYN时与商业Beacon试剂盒的检测结果高度一致.对大沙河水库中CYN的监测表明该毒素在水体中常年存在,但未超过WHO建议的安全限值.本研究发展的ELISA可实现水样和藻样中CYN的快速检测,为供水安全保障提供一种新的技术手段.     

渤海疏浚物中丁基锡提取方法优化及其分布特征

为了解渤海海域疏浚物中丁基锡(BTs,一丁基锡(MBT)、二丁基锡(DBT)、三丁基锡(TBT)之和)污染状况,选取渤海周边四个疏浚工程,采用单一变量法对沉积物中提取BTs的条件优化后分析疏浚物中BTs的含量.结果表明,活化铜粉添加量4.50g、二氯甲烷/二氯乙烷(V:V=1:1)混合萃取剂和0.5%的环庚三烯酚酮溶液是疏浚物中BTs提取最佳条件.渤海疏浚物TBT、DBT、MBT均被检出,其含量范围分别为2.93～7.96、1.07～2.27和4.99～9.00ng·Sn/g(干重,下同).大部分工程疏浚物中BTs含量空间分布总体呈距岸越近TBT含量越高的趋势,BTs含量与其他国家和地区的研究相比处于较低水平,且TBT均为历史输入.生态风险评价表明,渤海疏浚物中TBT的生态风险处于较低水平.但根据国际公约对疏浚物海洋倾倒的管理建议,有必要对研究区域疏浚物海洋倾倒活动进行持续关注或管控.     

重庆市河水中粪源微生物污染特征及源解析

以重庆主要河流水体作为研究对象,使用传统培养技术评估了细菌总数、粪链球菌、肠球菌、脆弱拟杆菌、总大肠菌群及粪大肠菌群的污染水平;同时以拟杆菌作为特异性指示菌,选取人源性粪便专一指示菌引物（HF183）和猪源性粪便专一指示菌引物（Pig-2-Bac）进行源追踪.微生物培养结果表明：重庆市主要河流在春季有15.4%的研究断面未达到Ⅲ类水质,秋季有61.5%的研究断面未达到Ⅲ类水质.在春季,主城区河流主要受人类粪便污染,区县河流主要受动物粪便污染;在秋季,主城区和区县河流都主要受人类粪便污染.指示微生物指标间Pearson相关性分析结果表明粪链球菌、粪大肠菌群、肠球菌两两之间有显著相关性,肠球菌与脆弱拟杆菌有显著相关性.猪源性拟杆菌特异性生物标记Pig-2-Bac和人源拟杆菌特异性生物标记HF183对人和动物粪便污染区分成功率达100%;用这两种特异性引物对春季水样DNA进行扩增,发现13个采样点均未受到猪源粪便污染,唐家沱、朝天门、鸡冠石、合川受到人源粪便污染.     

Estrogenic activities of two synthetic pyrethroids and their metabolites

Synthetic pyrethroids(SPs) are among the most common pesticides in current use,and so far,several SPs have been assessed for their potential estrogenicities by various methods.Previous studies have shown that the estrogenicities partly come from their metabolites.Although considerable information is available with respect to the metabolism and environmental degradation of SPs,little is known about the estrogenicities of the metabolites.In this study,permethrin(PM) and β-cypermethrin(CP),as well as their metabolites(3-phenoxybenzoic alcohol(PBCOH),3-phenoxybenzaldehyde(PBCHO) and 3-phenoxybenzoic acid(PBCOOH) were evaluated for their estrogenic activities in the MCF-7 human breast carcinoma cell line.In the MCF-7 cell proliferation assay,PM and CP exhibited significant estrogenic activities at 10-7 mol/L,comparable to 17β-estradiol(E2 ) of 10-9 mol/L,with the relative proliferative effect ratios of 55.4% and 56.3%,respectively.The real-time quantitative polymerase chain reaction(qRT-PCR) results confirmed the estrogenicities of PM and CP with significant alteration of pS2 and ERα mRNA levels observed at 10-6 mol/L.For the three major metabolites,PBCOH and PBCOOH exhibited estrogenic activities in all assays,while no significant estrogenic responses was observed for PBCHO compared to the vehicle control.In particular,PBCOH had even slightly stronger estrogenic activity than its parent compounds,indicating that metabolism may be one of the reasons for the estrogenicities of the SPs.Given the widespread use of SPs,the toxicological effects of parent compounds and their metabolites should be taken into consideration in the risk assessment of SPs.     

活性炭吸附处理黄磷化工渗滤液研究

研究了颗粒活性炭对黄磷化工渗滤液中有机物的吸附容量、吸附热力学和动力学。结果表明:颗粒活性炭对渗滤液中有机物的吸附容量几乎不受渗滤液pH值的影响,吸附45min后基本达到平衡。吸附等温线更符合修正的Freundlich模型,表明实验中的吸附主要是多分子层的吸附。拟二级动力学模型能更好的定量描述有机物在颗粒活性炭上的吸附过程,速率常数k2=0.12128g/(mg·min),平衡吸附量qe=5.78748mg/g。     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

四钛酸钾晶须对亚甲基蓝吸附性能研究

利用四钛酸钾晶须作为吸附剂,研究了亚甲基蓝在其上的吸附行为,考察了吸附体系pH值、吸附剂用量、吸附时间对其吸附效果的影响.实验结果表明,四钛酸钾晶须对亚甲基蓝有较强的吸附力,得到的吸附等温线能较好的符合Freundlich方程,其R2都能达到0.991以上,吸附动力学可以用拟二级动力学模型描述.在碱性范围内四钛酸钾晶须...