微波消解-ICP/MS法同时测定水产品中13种元素

用硝酸-双氧水体系微波消解,以In、Sc为内标,采用电感耦合等离子体质谱法（ICP／MS）同时测定水产品中V、Cr、C0、Ni、Cu、Zn、As、Se、Cd、Sb、Ba、T1、Pb等13种元素。各元素的检出限在0．05ng／g～0．064μg／g之间,样品平行测定4次的RSD〈5％,鲢鱼样品的加标回收率在81％～117％之间。     

固体进样-冷原子吸收法直接测定土壤中总汞

应用固体测汞仪,采用多标准土壤样品(n20)绘制校准曲线法和单一标准土壤样品绘制校准曲线法,分别对土壤中的汞进行测定。结果表明,两者的方法检出限分别为0.30、1.49 ng,平行样(n=6)的相对标准偏差分别为3.6%~4%、5.4%~9.0%,90 d内的重复性精密度为4.1%,对国家土壤标样进行测定,结果与标准值相符。表明与单一标准土壤样品绘制校准曲线法相比,多标准土壤样品绘制标准曲线法具有更好的精密度、更低的检出限,更强的适用性,并且由于校准曲线长期稳定性,有效缩短土壤中汞的检测周期。     

宁东能源化工基地固体废物中汞含量分布及对环境影响

通过分析宁东能源化工基地各大燃煤电厂以及煤化工厂固体废物样品,研究了固体废物中的汞分布规律及环境影响。结果表明:汞易在脱硫石膏、粉煤灰和气化粗渣中富集,汞浓度分别为0.16、0.24、0.15 mg/kg,而炉渣和气化细渣中的汞含量则相对较低,分别为0.05、0.03 mg/kg。通过化学组成及汞含量数据分析发现,出现这种情况的原因与汞本身易挥发的性质和固体废物的物化性质有关。此外,通过固体废物浸出毒性实验发现,脱硫石膏、粉煤灰、气化粗渣的浸出汞浓度小于浓度限值(0.1 mg/L),而气化细渣因锅炉回用,不参与填埋,汞又不易在炉渣中富集,故总体上宁东能源化工基地的固体废物无汞环境污染倾向。     

微波消解ICP-MS法同时测定大气颗粒物中多种痕量元素

采用微波消解电感耦合等离子体质谱法同时测定大气颗粒物中13种元素,选择硝酸体系消解20 min,硝酸加入体积为8 mL。Cu、Ni、Cr、Pb、Al、Mg、Mn、Ca在0μg/L～100μg/L,Ag、Ba、Co、Cd、Sn在0μg/L～5.00μg/L范围内线性良好,除Al、Mg、Ca检出限较高外,其他10种元素的检出限为0.07 ng/m3～1.82 ng/m3(按采样体积0.688 m3、定容体积50 mL计),滤膜样品平行测定3次的RSD≤1.2%,加标回收率在92%～108%之间。     

微波消解-原子荧光法同时测定TSP中砷和汞

通过比较不同滤膜的透气效率和空白值来选择采样滤膜,探讨了不同消解方法的前处理效果,进行精密性、准确性及实际样品测试等条件实验,建立了微波消解-原子荧光法同时测定大气环境TSP中砷和汞的方法。结果表明,过氯乙烯滤膜透气性好,空白值低且稳定,微波消解能使样品消解更完全,精密度好,回收率高,尤其汞的损失少。     

美国NIST元素汞发生器的基准溯源传递方法

综述了美国NIST元素汞发生器的基准溯源传递方法,通过在输出的汞标准气体中混合加入已知高纯度的201Hg0气体（201Hg2＋标准溶液还原雾化）,并采用同位素稀释电感耦合等离子体/质谱法（IDICP/MS）测量加标后201Hg/202Hg同位素丰度比例,计算出待溯源元素汞发生器输出的Hg0 质量浓度.该过程实现了从元素汞一级标准物质SRM 3133到201Hg2＋标准溶液,再到元素汞发生器输出标准气体的溯源传递,完成了从NIST元素汞基准到仪器供应商生产基准的一级溯源传递,为建立符合我国需求的元素汞溯源传递方法和形成元素汞发生器溯源传递能力提供借鉴.     

珠江河口沉积物Hg的分布与污染评价

利用Hg元素直测仪分析了珠江河口表层沉积物和柱状沉积物Hg的含量和背景值.沉积物Hg的背景值为(45.94～70.62)×10-9.表层沉积物Hg含量在(20.81～369.20)×10-9,平均为168.23×10-9,平面分布呈西部向东部和东南方向减少的趋势,其中,以西部浅滩沉积物Hg含量最高,富集程度最大.柱状沉积物Hg含量在(33.61～250.43)×10-9,平均含量150.49×10-9,垂直分布存在显著的地域差异,东滩沉积物Hg表现为上部富集,而西滩沉积物表现为均匀分布.地质累积指数法、潜在生态危害指数法和单因子污染指数法三种污染评价的结果表明,珠江河口表层沉积物的Hg污染区主要集中于西部浅滩,存在中等程度的Hg污染.     

袋式除尘器在国电九江电厂的应用及其对PM2.5的脱除分析

国电九江发电厂“上大压小”扩建工程2 x 660 MW超超临界燃煤机组配套采用旋转式低压脉冲袋式除尘器,对袋式除尘器进出口烟气中PM2.5、SO2、NO、SO3、氯化物、汞等浓度进行了现场测试,结果表明,该袋式除尘器能有效脱除烟气中的PM2.5,其PM2.5数浓度和质量浓度脱除效率可分别高达98.9%和99.7%,同时还可脱除富集在PM2.5表面的颗粒态汞。     

Neurologic features of chronic minamata disease (organic mercury poisoning) and incidence of complications with aging

Abstract

To elucidate the neurologic features of chronic Minamata disease, and the incidence of complications with aging, we studied 80 patients with documented Minamata disease (organic mercury poisoning) from 1986 to 1994 (mean age: 63 years). Of the cardinal neurologic findings, sensory impairment was seen with highest frequency in 98.8% of patients limited to the extremities in 86.3%. Impairment of lower extremity coordination was observed in 60%, constriction of the visual field in 51.9%, and retrocochlear hearing loss in 41%. To assess age‐related complications, patients were separated into three groups by age: Group I (10 to 39 years); Group II (40 to 69 years); Group III (≥7 0 years). The incidences of hypertension and cerebrovascular diseases, organic ophthalmologic disorders (including cataracts), presbyacusis, and cervical spondylosis deformans increased significantly with age. Compared with a preceding survey (1981 to 1985, 171 patients, mean age: 63.5 years), the incidences of complicated hypertension and cataracts had decreased, whereas those of cerebrovascular disease and retinitis pigmentosa remained unchanged. The incidences of abnormal brain computed tomography (CT), presbyacusis, cervical spondylosis deformans, and positive tests for urine sugar also increased. The incidences of these complications other than retinitis pigmentosa were similar to those in the general population. These results accurately reflect the recent epidemiological disease tendencies in Japan toward a decreased incidence of hypertension and an increased incidence of diabetes.     

Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry

A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg^?1 (square regression) and 250.0 and 2000.0 μg kg^?1 (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg^?1, respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.