氢化物原子荧光法测定稻谷中无机砷的研究

为研究稻谷中无机砷含量及分布,分别以稻谷、糙米、大米、米糠作为检验样品,采用氢化物原子荧光法测定无机砷;对无机砷的测定方法（GB／T5009．11原子荧光光度法）的实验步骤做了部分改进,加标回收率为93．8％～100．0％。     

Attenuation of inorganic arsenic and cadmium in rice grains using by-product iron materials from the casting industry combined with different water management practices

We examined the effect of two types of iron (Fe) material produced by the casting industry (spent steel shot [SSS] and residual iron material from steel shot production) on the mobility of arsenic (As) and cadmium (Cd) in soils. We also examined the uptake of these elements by rice plants (Oryza Sativa L.) under continuously flooded (CF) and water-saving (WS) cultivation. The application of both Fe materials (at 10 and 30 t ha^?1) strictly limited As mobilization in soils under CF cultivation. As a result, As uptake by rice plants declined, along with the total and inorganic As (iAs) concentration in rice grains. In comparison, As immobilization caused by the application of Fe material was less clear under WS cultivation. The rate of Fe material application was negatively correlated with As uptake by rice plants. It was also negatively correlated with total and iAs concentration in rice grains under both water management practices. The combination of applying Fe materials and WS cultivation decreased iAs concentration in rice grains to approximately one-fifth of that in rice grains produced from plants grown on soils without Fe material application under CF cultivation. CF cultivation strictly decreased dissolved Cd in soils, as well as Cd in rice grains with and without Fe material application. The application of Fe materials decreased Cd mobility and, hence, Cd uptake in rice plants, ultimately reducing the accumulation of Cd in rice grains under WS cultivation. Residual Fe material had a statistically greater effect at attenuating Cd accumulation in rice grains than SSS. The present study demonstrated the potential of combining by-product Fe material application and water management practices to attenuate iAs and/or Cd concentrations in rice grains. Practical countermeasures should be carefully adopted that consider the existing risks of iAs and Cd on each paddy field, and the combined effect of Fe material application and water management practices.     

Effects of arsenic supplementation in feed on laying performance,arsenic retention of eggs and organs,biochemical indices and endocrine hormones

1. The primary objective of this experiment was to estimate the toxic effects of arsenic (As) supplementation in feed on laying performance, As retention by eggs and organs, serum biochemical indices and endocrine hormones in laying hens.

2. A total of 320 “Jinghong Number 1” hens, 56-week-old, were randomly allocated into four treatments of four replicates with 20 layers in each. Graded arsenical was added to the basal diet in the experimental diets at As levels of 0, 17, 34 and 51 mg/kg, respectively. The trial lasted for 9 weeks including 1 week for acclimatisation.

3. Supplementation of dietary As for eight weeks had no effect on laying performance. As retention in albumen, yolk, egg, liver and kidney increased as As levels increased The level of serum phosphorus (P) was minimised at the 17 mg As/kg group. The activity of serum glutamic oxaloacetic transaminase (GOT) increased linearly. No differences were observed for levels of serum calcium (Ca), alkaline phosphatase (AKP) and serum glutamic pyruvic transaminase (GPT). Concentrations of estradiol (E₂) and progesterone (PG) declined at 34 and 51 mg/kg As levels compared with the control group. As supplementation exerted no influence on levels of serum follicle stimulating hormone (FSH), luteinising hormone (LH), triiodothyronine (T₃), thyroxine (T₄) and the ratio between T₃ and T₄.

4. In conclusion, dietary As supplementation accelerated retention in tissues and eggs, and affected the laying rate by diminishing hormone levels of E2 and PG at 51 mg/kg.     

琼脂培养基质条件下砷在水稻幼苗中的积累转运

[目的]研究砷（As）在水稻幼苗中的积累转运。[方法]利用琼脂培养基质模拟厌氧的湿地环境,在不同As浓度条件下对水稻幼苗进行培养。[结果]培养基质中的As对水稻根部干重没有显著影响,对地上部干重产生了显著抑制作用。低剂量的As可以促进部分水稻品种干物质的积累。水稻根系对As具有较强的吸收积累能力,As被根系吸收后多数被固定于根部,只有少量被转运至茎叶,二者呈极显著正相关关系。[结论]该结果为进一步研究As在水稻中的积累转运规律提供了重要的理论依据。     

阳宗海水体中砷的形态分布特征及来源研究

采集云南阳宗海湖水和表层沉积物样品,运用地球化学的原理与方法研究了高原湖水环境中砷（As）和其他重金属的含量、存在形态及空间分布,采用原子荧光分光光度法直接分析了样品中As的形态,并在此基础上对其健康危害风险进行了评估。结果表明,该湖泊水体中As的污染已达到较高的水平,对水域周围环境造成较高的环境健康危害风险。湖水中As（Ⅲ）的含量为51.4～350.7μg/L,平均含量为84.0μg/L;As（V）的含量为66.1～988.7μg/L,平均含量为156.1μg/L;总As含量平均值为167.0μg/L。其中该湖泊泉水中As（Ⅲ）的含量为17500.0μg/L,As（V）的含量为12200.0μg/L,具有极高的健康危害。湖水中其他重金属如Fe、Mn、Cu、Zn、Co、Pb的含量均好于国家Ⅱ类水标准,Ni、Cd超国家IV类水标准。结果还表明,该高原湖泊As的存在形态及分布特征与某工厂的排污活动相关。     

四川震毁企业场地健康风险评估实例研究

2008年汶川大地震使一些损毁企业的原料、中间产品等发生泄漏,这些泄漏物以及损毁企业长期积存的有害废物对环境产生了巨大的污染风险。以德阳市一家损毁的磷制品企业为例,运用单因子污染指数法和《污染场地风险评估技术导则》中的健康风险模型,详细地评价了场地砷的健康风险。评价结果显示,在初步评价的3种有害元素中,与启动风险筛选值相比,砷的污染指数最高,达到了50,因此砷被确定为该场地的风险因子。深度评价中,砷在不同用地模式下的健康风险均是不可忽视的,且最高危害指数达1.01E-04。场地砷的致癌风险较大,若想再利用则必须经过修复,消除风险之后才可以正常使用。     

微波消解原子荧光光谱法快速测定食品中汞和砷的方法研究

建立了一种采用微波消解一次样品前处理、原子荧光法依次快速测定食品中汞和砷的方法。通过条件优化,该方法汞和砷的检出限分别为0.023μg/L、0.119μg/L;试样测定精密度(RSD),汞和砷分别为6.2%、3.3%;加标回收率,汞和砷分别在96.0%~105.0%、95.9%~102.5%。标准物质测定结果符合要求。该法简便、快速、灵敏,能够满足食品的检测要求。     

郑州市城市土壤砷含量的分布特征及其成因探讨

在对郑州市城市土壤采样分析的基础上,探讨了土壤中As的含量、分布、成因及其与人类活动的关系.结果表明,郑州市城市土壤表层土壤的平均As含量为7.67 mg/kg,变幅为3.25～10.00 mg/kg,未达到污染的水平;但城市土壤中As含量普遍高于郊区对照样,城市土壤高As值区位于老居民区、文教区和商业区.郑州市城市土壤As含量自表层向下没有一定的分布规律,且与土壤理化性质之间没有相关关系;其主要与人类活动强烈干扰有关,是典型的人为源重金属元素.城市土壤外源性As的输入主要是工业"三废"和市民日常生活中所丢弃的含As废物.     

盘州市三大茶区土壤重金属和砷的监测与评价

为了研究盘州市老厂、火铺、保基3个乡镇土壤中铜(Cu)、铬(Cr)、镉(Cd)、铅(Pb)、汞(Hg)5种重金属和砷(As)的浓度及污染水平,用多点采集混合法制得72份土样进行测定、分析。结果表明,盘州市三大茶区大部分的土壤质量符合无公害茶园土壤环境标准,但个别区域因重金属和砷的含量较高,不宜种植无公害有机茶叶。火铺、老厂2个乡镇茶区土壤的单因子污染指数和综合污染指数均<1,表明其土壤未受到重金属和砷的污染,属安全、清洁水平;保基乡茶园土壤因重金属(Cd)单项污染指数>1,综合污染指数介于0.7～1.0之间,即茶区土壤和作物已被重金属(Cd)轻度污染,综合污染级别属警戒范围。     

渤海中部海域水体中Hg、As的时空分布特征

本研究分析了2013年5月(春季)、7月(夏季)、11月(秋季)、12月(冬季)渤海中部海域表、中、底层海水中汞(Hg)、砷(As)两种元素的时空分布特征。结果显示,Hg 的含量范围为0.0029–0.3926μg/L,平均含量为0.0676μg/L。从垂直分布来看,水体中Hg的含量呈现底层>中层>表层的变化特点;从四季的变化特点看,水体中Hg的含量呈现春季>冬季>秋季>夏季的变化规律,其中,仅有夏季表层水体达到国家海水水质标准(GB3097–1997),其余水体中 Hg 的含量均有超标现象发生。As的含量范围为0.65–10.83μg/L,平均含量为1.50μg/L,除夏季表层水体中的As含量较高外,水体中的As均呈现均匀的分布模式。从垂直分布来看,As在四季的平均含量均表现为表层>中层>底层,且均未超出国家海水水质标准。研究表明,渤海中部海域水体中,As 的含量均达到Ⅰ类水质标准(20μg/L),而Hg含量却频频超出Ⅰ类水质标准(0.05μg/L)或Ⅱ类水质标准(0.20μg/L)。渤海中部海域水质已经受到了重金属的污染,推测该现象主要源于人类活动的影响。