脲酶抑制法检测环境样品中重金属离子研究

为探索利用脲酶快速检测环境样品中重金属离子的最佳条件，系统研究了重金属和缓冲液类型及其浓度对脲酶抑制率的影响。结果表明，不同浓度缓冲液中重金属离子浓度与脲酶抑制率呈显著的相关性，表现为随着重金属离子浓度的增加，脲酶抑制率也提高。缓冲液类型和浓度均能影响重金属对脲酶的抑制作用，其中磷酸缓冲液中，无论是Hg^2 还是Cu^2 对脲酶活性均有较强的抑制作用：在柠檬酸缓冲液中2种离子对脲酶的抑制作用存在显著差异。建立脲酶抑制检测技术的关键是选择合适的缓冲系统。此结果为脲酶抑制法在快速检测重金属离子中最佳检测条件的选择提供了理论依据。     

检测水中亚硫酸还原厌氧梭菌孢子的培养液富集法

水体中亚硫酸协还原菌的孢子，能在水中生存较长时间，容易在水池或管道中滋生，产生黑臭，可作为水体长期或周期性污染的一种指示，但目前国内尚无测定该菌的完整方法，作者建立了一种比较适合我国国情的测定方法，以国产蛋白陈替代胶胨型的水解液，结果阳性特征明显，精密度，重现性均较好。     

水中硫化物在线检测仪的研制

介绍硫离子在线检测仪的测定原理和基本系统结构,仪器采用流动注射法(FIA),具有测定周期短、试剂用量少的优点,该方法(显色剂为对二甲氨基苯胺)测定波长为665nm,工作范围ρ=2.0～25.0mg·L-1。回收率为96.1%～101.8%。     

Enhanced twin pregnancy detection within an open neural tube defect and down syndrome screening protocol using free-beta hCG and AFP

We have applied our multimarker approach of maternal serum alpha-fetoprotein (AFP) and free-beta human chorionic gonadotropin (hCG) for Down syndrome screening to multiple gestations to assess its efficacy for improved detection of twin and triplet pregnancies. This study matched 225 cases of twin pregnancy and 39 cases of triplet pregnancy each with ten singleton pregnancies based on gestational week, race, time to receive sample, time of year of sample, and geographical area. The ratios of the MOM for each group at the tenth, 50th, and 90th percentiles were compared by the Wilcoxon test. Risks for twins were calculated using Bayes' rule, the age-related incidence of twins, and the levels of AFP and free-beta hCG. The tenth, 50th, and 90th percentiles of free-beta hCG MOMs in twin and triplet cases were 0.85, 1.99, and 4.51, and 1.38, 2.78, and 4.07, respectively. For AFP, the MOMs at these percentiles were 1.26, 1.91, and 2.99, and 2.02, 2.68, and 5.30, respectively. The twin and triplet distributions for each marker were statistically significantly different from the singleton distributions (P<0.0001) and from each other (P=0.0012). At a twin risk cut-off of 1 in 50, 77.4 per cent of all twin gestations can be detected in a second-trimester AFP and free-beta hCG screening protocol with 5.1 per cent of singleton pregnancies falsely identified as at risk for twins. Our dual marker protocol for mid-trimester pregnancy screening combining AFP and free-beta hCG can identify over 77 per cent of twin pregnancies in women less than 35 years of age. This benefit may contribute to an improved outcome of pregnancy by early detection of multiple gestation.     

Use of the chemical cleavage of mismatch method for prenatal deficiency diagnosis of alpha-1-antitrypsin

The most common mutation in alpha-1-antitrypsin deficiency, conversion of a G to an A at base 9989 (PI-Z), was detected with the chemical cleavage of mismatch method, demonstrating the power of the method for prenatal diagnosis. Exon V of the gene was amplified using the polymerase chain reaction and heteroduplexes were formed to test for the presence of the mutation. The predicted C mismatch was readily detectable with hydroxylamine, and by making the probe from the chorionic villus sample it was possible to determine that the fetus was heterozygous, not homozygous, for the mutation.     

吹扫捕集与色谱质谱联用测定水中挥发性有机物

采用吹扫描集与色谱质谱联用的对水中１９种挥发性有机物同时进行富集分离，定性和定量检测，结果表明，不同化合物的平均回收率大于９０％相对偏差小于５％，该方法的检测限约为０．１－０．４μ／Ｌ。实验证明吹扫描集与色谱质谱联用技术是快速测定水中挥发性有要峨的有效手段。     

关于小于检出限监测结果表示方法的探讨

在环境监测中，在上报结果小于检出限时，以“未检出”、“零”、“无”或“０００…ｎ”等来表示都是不妥当的，会给环境管理和数据使用带来不良影响，甚至会误导出错误的结论。对于此类结果，应以“小于检出限”表示为好。     

废水中优先控制污染酚的HPLC分离-电化学检测

研究了 HPL C分离 -安培法检测四种优先控制污染酚的色谱条件。在 Shim- pack CL C- ODS柱上 ,以 0 .1mol/L Na H2 PO4 +0 .0 5 mm ol/L EDTA· 2 Na+1% CH3 COOH(p H3.0 ) +5 0 % CH3 OH作流动相 ,氧化电位 +1.0 V检测。工作曲线的线性范围在 0～ 30μg/ml,检测限达 ng/m l     

太湖水-气界面CO2交换通量观测研究

基于2003-01～2005-06利用静态箱法对太湖水-气界面CO₂交换通量的观测,对太湖水-气界面交换通量的变化特征进行了分析研究.结果表明:太湖水-气界面CO₂交换通量存在明显的日变化,春、夏、秋、冬4季日平均通量分别为-0.79mg/(m²·h)、-4.89 mg/(m²·h)、-4.06 mg/(m²·h)和-2.56 mg/(m²·h),太湖均是CO₂的汇.一般污染越重的区域,CO₂通量值越大.藻型湖区水-气界面CO₂交换通量季节变化不明显,草型湖区水-气界面CO₂交换通量季节变化很明显,夏秋季高,冬春季低.CO₂通量变化的可能相关因子还有天气情况、太阳辐射、风速及水温、pH、TA、Chla、TC、TN和TP等.     

Detection of Escherichia coli in wastewater based on enzyme immunoassay

This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay (ELISA) for Escherichia coli in drainage of wastewater treatment plants. Optimized conditions such as the reaction format (sandwich or direct), the concentrations of diluted horseradish peroxidase (HRP)-E. coli conjugate, and anti-HPR antibody and pretreatment of E. coli were studied. Those results showed that the linear range of detection for E. coli was 10 cfu/mL-6 × 10⁴ cfu/mL. Compared with conventional methods, it is a convenient and sensitive detection method with low cost. Translated from Environmental Science, 2005, 26(5): 128–131 [译自: 环境科学]