硝酸铅和金属铅作为对照品测定铅含量方法的探讨

探讨了硝酸铅和金属铅作为对照品测定铅含量的方法。结果表明,二者铅的测定值没有明显差异(P≥0.05),硝酸铅溶液比金属铅溶液相对稳定,因此,以硝酸铅代替金属铅作为对照品,操作简便、使用安全,具有较强的实际应用价值。     

大孔螯合树脂对沙棘原汁降铅工艺的研究

因产区土壤铅含量偏高或在加工过程中被污染,导致沙棘原汁中的铅含量超标,影响了产品的品质,本文研究了树脂吸附法降低沙棘原汁中的铅含量,利用不同型号和不同种类的树脂对沙棘原汁进行分析处理,实验结果表明:采用D363和D851伯胺两种树脂先后处理,对沙棘原汁的降铅效果较好,并保持了沙棘原汁中Vc和营养成分的含量,感官指标基本稳定,树脂在吸附饱和时经洗脱、再生,可反复利用,经济适用。     

仔猪轮状病毒感染与乳糖不耐受症的临床检测

[目的]探讨轮状病毒感染与乳糖不耐受症的临床相关性,为建立适用于规模化养猪场的仔猪轮状病毒感染检测方法提供理论依据.[方法]随机选择腹泻仔猪和健康仔猪各63头,采用醋酸铅—氢氧化铵法和pH试纸法分别检测仔猪粪便的乳糖和pH值,粪便乳糖大于或等于++且pH≤5.5为继发性乳糖不耐受症;然后运用猪轮状病毒诊断试剂检测乳糖不耐受病例的猪轮状病毒感染情况.[结果]与健康仔猪相比,腹泻仔猪粪便乳糖大于或等于++为36例,其中pH≤5.5有23例,即发生乳糖不耐受症的病例23例,占总腹泻仔猪数的36.51%.对23例乳糖不耐受病例进行轮状病毒感染检测,结果发现仔猪继发性乳糖不耐受症与猪感染轮状病毒所引起腹泻的吻合率高达100%.[结论]由猪轮状病毒所引起的仔猪腹泻,多会发生继发性乳糖不耐受症,采用醋酸铅—氢氧化铵法能及时鉴别诊断猪轮状病毒感染,且具有廉价、方便、快捷等优势,适合在基层猪场大规模使用.     

黄芪多糖(APS)拮抗铅镉联合致鸡脾脏细胞凋亡作用的研究

为了探讨黄芪多糖注射液对铅镉联合致鸡脾脏细胞凋亡的拮抗作用。采用TUNEL法、RT-PCR和DNA ladder方法检测分别对对照组、铅镉组和黄芪多糖-铅镉组的鸡脾细胞凋亡率和脾淋巴细胞凋亡基因Bcl-2 mRNA转录水平。结果表明：与对照组比较,试验组的细胞凋亡率明显升高,Bcl-2mRNA表达水平降低;试验组和对照组差异显著或差异极显著,并且黄芪多糖-铅镉组数据介于对照组和铅镉组之间。试验结果显示：黄芪多糖注射液对铅镉联合致鸡脏脾细胞凋亡具有明显的拮抗作用。     

Lead (Pb) accumulation,oxidative stress and DNA damage induced by dietary Pb in tilapia (Oreochromis niloticus)

With the increasing occurrence of dietary lead (Pb) contamination in aquaculture, a better understanding of the toxic effects of dietary Pb on aquatic animals is needed. Tilapia (Oreochromis niloticus) were exposed to dietary Pb at concentrations of 0, 100, 400 and 800 μg g^?1 dry weight for 60 days, and Pb accumulation in tissues and blood, oxidative stress in posterior kidney and DNA damage in peripheral blood cells were investigated. The results showed that dietary Pb exposure resulted in significant Pb accumulation in tissues and blood, which increased with the dietary Pb concentrations. Pb accumulated in sampled tissues in the following order: posterior kidney>bone>liver>gill>spleen>testis>muscle>brain. Dietary Pb caused a significant increase in the malondialdehyde level and a significant decrease in the total antioxidant capacity content when compared with the control group (P<0.05), accompanied by concentration‐dependent decreases in the glutathione content, glutathione peroxidase and superoxide dismutase activities. Pb dose‐dependent DNA damage was observed in peripheral blood cells of tilapia exposed to dietary Pb. The results suggest that dietary Pb exposure can induce significant Pb accumulation in tissues and blood, followed by oxidative stress in posterior kidney and DNA damage in peripheral blood cells of tilapia.     

修复剂及其施用水平对广西高铅污染土壤的影响

为降低高铅污染土壤对农作物的毒害,通过采用水浸取、DTPA浸取单步浸取试验,研究不同类型修复剂对广西环江、阳朔2个地区的高铅污染土壤的影响。结果表明,随着施加水平的增加,各个修复剂对土壤pH增加幅度的大小顺序是：有机肥>磷矿粉>钙镁磷肥>生石灰,磷矿粉、有机肥能够提高供试土壤的pH。磷酸二氢钾、过磷酸钙（高、中、低）均显著降低土壤DTPA-Pb含量,分别为32%~72%、31%~57%;而磷酸二氢钾对水溶态铅含量的影响与之相反,增加了水溶态铅含量1~3.4倍,过磷酸钙（高）显著地降低了水溶态铅含量,降低水溶态铅含量约88%。有机肥能够通过降低土壤水溶态铅的含量,增加了DTPA的浸取率。对供试土壤S-1,生石灰、有机肥、磷矿粉均显著降低了土壤中水提取态铅的含量,土壤水提取态铅含量均为低浓度处理>高浓度处理;对供试土壤S-2,有机肥、磷矿粉在不同施加浓度均显著地降低了水溶态铅的含量,降低为41%~55%。     

Chemometric Methods to Predict of Pb in Urban Soil from Port Pirie,South Australia,using Spectrally Active of Soil Carbon

A total of 73 soil samples were initially analyzed for lead (Pb) concentration as an indicator of the environment impact of smelter activity in the Port Pirie, South Australia. Chemometric techniques were used to assess the ability of near-infrared (NIR) reflectance spectroscopy to predict soil Pb using spectrally active soil characteristics such as soil carbon (C). The result indicated a strong linear relationship between log-transformed data of soil Pb and spectral reflectance in the range between 500 and 612 nm with R² = 0.54 and a low root-mean-square error (RMSE_v = 0.38) for the validation mode with an acceptable ratio of performance to deviation and ratio of error range (1.6 and 7.7, respectively). This study suggested that NIR spectroscopy based on auxiliary spectrally active components is a rapid and noninvasive assessment technique and has the ability to determine Pb contamination in urban soil to be useful in environmental health risk assessment.     

外源铅在土壤中的年际变化及对土壤有机碳矿化和速效养分的影响

以关中土为供试土样进行田间试验,向耕层土壤中添加不同浓度外源铅(Pb0:背景值,CK;Pb1:175 mg·kg~(-1)+背景值;Pb2:350 mg·kg~(-1)+背景值),进行小麦—玉米轮作试验。分别于2011—2013年小麦收获季采集耕层(0~20 cm)土壤,分析土壤中铅全量及有效态铅含量的年际变化,以及铅对小麦-玉米轮作模式下土壤有机碳(SOC)、溶解性有机碳(DOC)、微生物量碳(MBC)、碱解氮、速效磷、速效钾含量的影响。结果表明,三年中,施铅处理下土壤中铅全量及有效态铅含量分别下降13.22%和30.65%,总体呈现逐年下降趋势。与对照(CK)相比,Pb1、Pb2处理下SOC平均含量分别下降了16.30%和11.86%;DOC平均含量分别下降了4.05%和7.34%,与土壤铅含量呈现显著负相关关系;低浓度铅污染下土壤微生物商(q M)显著高于对照土壤,微生物量碳含量变化不显著。此外,土壤速效养分的分析显示,土壤碱解氮含量在外源铅加入初期下降明显,且在Pb1处理下碱解氮减少量最大;土壤速效磷含量随土壤铅含量增加而呈现下降趋势;土壤速效钾含量则随土壤铅含量的增加而增加。试验表明,外源铅的加入影响了土壤有机碳的稳定性,对土壤碳、氮循环产生了一定的影响;能够与土壤溶液中的磷酸根生成难溶性盐,与土壤胶体或土壤矿物晶格中的K+发生置换,加大土壤速效养分的流失风险。     

Effects of compost amended lead–arsenate contaminated soils on total and inorganic arsenic concentrations in rice

Rice (Oryza sativa L.), a staple crop for over 50% of the world's population, is also a source of dietary arsenic (As) because of it's efficiencyat accumulating As. Lead–arsenate pesticide was used in agriculture, these soils potentially may be used for rice production. The objective of this study was to determine the effects of compost on total and inorganic As concentrations in rice grown on lead–arsenate contaminated soils. Three lead–arsenatesoils were amended with 10% by weight of compost and planted with rice under flooded and non-flooded conditions. Rice grain yieldwas higher with compost but not flooding. Flooding significantly increased total and inorganic As concentrations. In most cases, rice inorganic Asconcentrations were higher than the limit set by Chinaat 0.2 mg kg^?1. Compost at therate used did not reduce rice grain As to safe levels.Lead–arsenate contaminated soils are not recommended for rice production.