川芎根茎组织部位对镉的富集能力探索

目的初步探索川芎根茎不同组织部位对镉的富集能力,以期为解决川芎药用部位镉超标提供实验依据。方法采用原子吸收分光光度法,测定经V(硝酸)+V(高氯酸)=4+1消解体系消解的川芎药材、川芎根茎皮部及根茎皮部以外组织中的镉含量。结果市购的3批川芎药材中镉含量均超出国家标准(0.3 mg·kg-1),且川芎根茎不同组织部位中镉含量差异显著,川芎根茎皮部镉含量分别高出皮部以外组织镉含量的1.70,1.25,3.37倍。结论新老产区的川芎药材均有不同程度的镉污染情况,川芎根茎皮部具有明显超镉富集作用,是川芎根茎积累镉的主要部位。     

川芎中重金属元素镉含量测定的研究进展

川芎中有毒重金属元素镉含量超过国家GAP标准,严重影响其出口创汇,也成为制约川芎走向现代化和国际化的瓶颈。介绍了目前对川芎的消化及重金属元素镉的检测方法,并对各方法的利弊进行了分析,从而为准确、高效地检测药材中重金属元素镉的含量提供了有力的参考依据。     

成都市土壤-植物系统中镉的分布特征

对成都市蔬菜及根系土中镉含量数据进行了综合分析。结果发现,成都市土壤镉存在明显的区域分布规律;镉在莴笋体内主要分布在叶片部位;土壤和植物中镉的总量无显著相关关系,可为给城市的环境规划及治理提供科学依据。     

豫产桔梗的土壤与药材中部分微量元素含量与分析

为了解桔梗中微量元素含量特征,研究土壤中微量元素对桔梗药材道地性的影响,采用原子吸收光谱法、冷原子荧光法、双道原子荧光法对不同产地的桔梗药材及生境土壤中8种微量元素含量进行了测定,所得数据用SPSS 11.0软件进行分析比较。结果表明,不同产地的桔梗微量元素含量有差异;药材与土壤中微量元素之间具有相关性。桔梗对土壤中微量元素是主动与被动相结合的有选择吸收。     

涡旋提取-石墨炉原子吸收光谱法测定土壤中有效态镉

土壤作为农业生产的重要载体,是保障农产品质量安全的关键源头。近年来,随着经济的快速发展,土壤中重金属污染问题日益凸显,已成为世界性的重大环境问题之一。目前针对土壤中重金属的调查分析大多处于总量水平,这并不能全面地评价重金属的生态风险,因为土壤-重金属-生物体之间存在复杂的动态相互作用,土壤中只有部分重金属能被生物体吸收,这部分能被生物体吸收利用的元素以特定的形态存在,这种特定的形态被称之为有效态。土壤中重金属能否被植物吸收主要取决于该元素的有效态[1],因此土壤中重金属有效态含量的测定,对评价和控制其生物毒害作用具有更实际的意义。镉是生物蓄积性强、具有"三致"作用的剧毒元素,会通过食物链富集到人体,从而对人体健康造成危害[2]。目前我国暂未制定土壤中有效态镉的限量标准,关于土壤中有效态镉含量测定方法的研究也较少[3-5],国家标准方法 GB/T 23739-2009(S)《土壤质量有效态铅和镉的测定原子吸收法》前处理采用振荡器低效提取,提取时间长,试剂用量大,提取液根据含量高低选用火焰原子吸收光谱仪或者石墨炉原子吸收光谱仪,操作较繁琐,无法满足批量样品快速分析的要求。文献[3-4]采用超声提取-电感耦合等离子体质谱法,前处理操作简单,但仪器成本较高,方法应用的推广有一定的局限性,且由于土壤样品基体复杂,容易堵塞雾化器导致仪器故障。     

大米中镉检测能力验证

镉是剧毒物质,常通过土壤或水被农作物(特别是水稻等)吸收。世界各国对大米中镉含量均有严格限制,我国粮食卫生标准GB 2715—2005中镉的限量为0,2 mg·kg~(-1)。近年来,国家大米监督抽查结果显示,我国南方部分省份的大米镉含量超标,据调查环境污染是造成大米中镉超标的主要原因。本工作通过对2008年国家认监委能力验证计划《大米     

改性活性炭对土壤镉的吸附性影响

目的研究3种改性活性炭对菜地、河流底泥、荷花底泥镉吸附性的影响。方法对活性炭进行酸改性、碱改性和氧化改性,采用双硫腙分光光度法测定镉含量。结果对实验土样,最佳活性炭添加量为0.025 g/g。随着初始镉含量的升高,土壤对镉的吸附量不断增大。结论 3种改性活性炭相比普通活性炭对湿地土壤的镉吸附量均有不同程度的提升,荷花底泥中,酸性、氧化改性活性炭相比普通活性炭,吸附效果提高7.7%,8.3%,吸附效果提升显著。     

电感耦合等离子体质谱法测定土壤中镉和总汞

建立电感耦合等离子质谱法测定土壤中镉和总汞的方法。土壤样品在电热板上用盐酸和硝酸于100℃低温消解,重量法定容,取上清液上机测定。镉和总汞含量分别在0.502~10.20 ng/g,0.212~5.010 ng/g范围内线性良好,相关系数(r2)大于0.999,土壤中镉和总汞的检出限分别为0.021,0.002μg/g,测定结果的相对标准偏差分别为1.99%,5.57%(n=6),加标回收率分别为97.5%~101.1%,87.5%~92.9%。该方法样品处理简单快捷,检出限低,准确度和精密度高,适合土壤中镉和总汞含量的测定。     

湿法消解–石墨炉原子吸收标准加入法测定土壤中的镉

土壤样品经过硝酸–氢氟酸于130℃加热回流处理后,采用石墨炉原子吸收标准加入法测定半消解样品中镉的含量。以5%氯化铵或0.1%硝酸钯作为化学改进剂,灰化温度为500℃、原子化温度为2 000℃。当标准系列吸光度在0.18以内时,镉标准溶液的质量浓度在0~3.0μg/L内与吸光度呈良好的线性,相关系数r=0.998 6,方法的检出限为0.02 mg/kg,实际样品测定结果的相对标准偏差为3.93%~5.30%(n=5)。用该法与国标方法对土壤标准样品进行测定,两种方法测定结果一致。该法快速、简便,适用于土壤中镉含量的快速检测。     

原子吸收光谱法测定大承气颗粒剂中砷铅镉铬汞的含量

采用原子吸收光谱法测定了大承气颗粒剂及其原料药材中砷、铅、镉、铬和汞的含量，并参照食品中重金属的限量规定进行了比较。结果表明，大承气颗粒剂及其原料药材中的砷、铅、镉、铬和汞均低于限量标准，成品中重金属的含量均低于原料药材中的平均含量，这为大承气颗粒剂生产中的质量控制提供了依据。     

离子色谱法同时分析中药中的碱金属与碱土金属离子

用离子色谱法简单快速地分析了中药中的阳离子。分析结果表明,川芎和酸枣仁中5种常见阳离子Na~+,NH~+_4,K~+,Mg~2+和Ca~2+的含量比例不同。各离子的检出限（S/N=3）为0.001～0.013mg／L,线性范围达3个数量级。     

Cadmium analysis in soil by microwave acid digestion and graphite furnace atomic absorption spectrometry

The need to determine micronutrients and toxic elements in soils has grown in recent years and cadmium is of special interest. A method has been developed for the determination of cadmium in soils based on a prior acid digestion of the samples with nitric acid in closed Teflon vessels, into a microwave over. The cadmium determination was carried out by graphite furnace atomic absorption spectrometry (GFAAS) with Lvov platform. Optimum operating conditions, analyte modifiers and matrix interferences have been investigated. The best matrix modifier was found to be ammonium dihydrogen phosphate. The interferences are greatly reduced under these operating conditions and calibration can be performed with simple aqueous solutions of the metal standard. The method is rapid and provides accurate and precise results that agree with certified values for two reference materials: BCR 141 (calcareous loam soil) and BCR 277 (estuarine sediment).     

Environmental cadmium, lead and nickel contamination: possible relationship between soil and vegetable content

Summary The cadmium, lead and nickel content of soils of four agricultural areas exposed to different degrees of environmental pollution and vegetables grown there were measured by Atomic Absorption Spectrophotometry (AAS). In order to ascertain the possible relationship between the heavy metal content of soils (total and extractable) and of vegetables grown in them, the correlation between the two was calculated. The highest correlation values between metal content of soil and vegetables are these corresponding to nickel: the total metal content in soils and leaves-stems are linear (p<0.01). The extractable metal content of soils and leaves-stems are linear (p<0.1). Therefore, soil seems to be the main contributor to nickel content of plants (leaves-stems). In the case of cadmium a statistically significant linear correlation (p<0.01) was observed between total metal content in soil and in leaves-stems and a negative one between extractable metal content of soils and that of roots-bulbs. For lead a negative correlation was found between extractable metal content of soils and leaves-stems. In any case, the lead content of soils is not the main factor that influences the lead content of vegetables. Anthropogenic and environmental factors play a more important role than the lead in soils in the lead content of vegetables.     

Exploratory analysis of chromatographic fingerprints to distinguish rhizoma Chuanxiong and rhizoma Ligustici

Identification and quality control of products of natural origin, used for preventive and therapeutical goals, is required by regulating authorities, as the World Health Organization. This study focuses on the identification and distinction of the rhizomes from two Chinese herbs, rhizoma Chuanxiong (from Ligusticum chuanxiong Hort.) and rhizoma Ligustici (from Ligusticum jeholense Nakai et Kitag), by chromatographic fingerprints. A second goal is using the fingerprints to assay ferulic acid, as its concentration provides an additional differentiation feature. Several extraction methods were tested, to obtain the highest number of peaks in the fingerprints. The best results were found using 76:19:5 (v/v/v) methanol/water/formic acid as solvent and extracting the pulverized material on a shaking bath for 15 min. Then fingerprint optimization was done. Most information about the herbs, i.e. the highest number of peaks, was observed on a Hypersil ODS column (250 mm × 4.6 mm ID, 5 μm), 1.0% acetic acid in the mobile phase and employing within 50 min linear gradient elution from 5:95 (v/v) to 95:5 (v/v) acetonitrile/water. The final fingerprints were able to distinguish rhizoma Chuanxiong and Ligustici, based on correlation coefficients combined with exploratory data analysis. The distinction was visualized using Principal Component Analysis, Projection Pursuit and Hierarchical Clustering Analysis techniques. Quantification of ferulic acid was possible in the fingerprints of both rhizomes. The time-different intermediate precisions of the fingerprints and of the ferulic acid quantification were shown to be acceptable.     

镉对植物根系的毒害作用

镉是一种毒性很强的重金属,可严重影响植物的生长。当镉对植物产生毒害作用时,首先表现在根系的形态和生理功能改变上。综述了镉胁迫下植物根系的形态学变化及生理生化改变,以及镉在植物体内的代谢过程,初步探讨了根际土壤对植物吸收镉的影响,并简单介绍了目前测定根系指标的常用方法。     

GC-MS fingerprints for discrimination of Ligusticum chuanxiong from Angelica

A GC-MS fingerprinting technique based on the essential oil components has been developed for the discrimination of chuanxiong against Chinese Angelica (Angelica sinensis (Oliv.) Diels) or other herbs with similar compositions. The analytical performance of four different extraction methods for the separation of essential oil components have been compared and these include: ultrasound-assisted extraction (UAE), supercritical fluid extraction (SFE), Soxhlet extraction (SHE) and hydro-distillation extraction (HDE). The results showed that UAE was the most effective extraction method, and the operational parameters of UAE were optimized. 3-Butylphthalide, Z-butylidenephthalide, senkyunolide I, senkyunolide H, E-butylidenephthalide, senkyunolide A, neocnidilide, Z-ligustilide and E-ligustilide were tentatively identified in chromatograms of chuanxiong based on their GC-EI-MS data. Similarity coefficient calculations based on correlation methods have been performed on the GC-MS fingerprints. Using an authentic standard Chuanxiong as the reference, the similarity coefficients between the standard and all other chuanxiong samples ranged from 0.90 to 1.0 (with 1.0 being the perfect match), which as a group can be readily separated from the Angelica samples for which the similarity index against the chuanxiong standard ranged from 0.75 to 0.77. Conversely, when an authentic Angelica standard was used as the reference, the respective similarity coefficients fall in the range of 0.70-0.75 and 0.98-1.00 for the chuanxiong and Angelica sample groups. Our results thus demonstrate that the fingerprinting technique developed in the study can indeed discriminate the two herbs with high reliability.     

金华地区饲料中铅、镉的检测

通过对金华地区多家饲料生产厂家所生产的饲料进行抽样调查,利用原子吸收分光光度计测定了饲料中铅、镉的含量。结果表明,所测饲料原料样品中,铅、镉的含量完全符合国家标准规定,合格率100%;铅、镉含量分别在0.005~0.157 mg/kg和0.06~0.104 mg/kg范围内,铅含量最高的是玉米为0.157 mg/kg,最低的是蚕豆为0.005 mg/kg;镉含量最高的是骨粉为0.104 mg/kg,最低的是豌豆和蚕豆为0.006 mg/kg。金华市饲料中铅、镉含量符合国家饲料卫生标准,可以安全喂养牲畜。     

The Analysis of Inorganic and Organic Pollutants in Soil with Special Regard to Their Bioavailability

Abstract

The most important inorganic pollutants in soil are the heavy metals. Problems related to the determination of the total and soluble content are discussed. Soluble contents are of interest in connection with studies about bioavailability. Because some of the heavy metals are essential for plant growth, most of the work about bioavailability has been done in the field of plant nutrition. Much less is known about the situation in polluted soils.

It was shown that neutral salt solutions which do not really change the pH of soil during the extraction procedure are best suited to define thresholds of excess. This is in contrast to much stronger extractants like EDTA or DTPA often proposed for the analysis of soils which are deficient in trace elements.

With three sets of experiments the correlation between the contents of cadmium, copper, nickel and zinc extracted by 0.1 M NaNO₃ (as an example of a neutral salt solution) and the plant response (phyto- or zootoxicity) are shown:

—pot experiments using soils which were contaminated by metal salt solutions

—pot experiments using soils from contaminated areas

—field studies in polluted areas. In these studies the aspect of heavy metal leaching was also considered.

The results were converted to indicative values in the Swiss Ordinance of Pollutants in the Soil. These indicative values derived from plant reactions were checked by the carbon mineralisation as an example of a soil microbiological process.

As it was found that organic pollutants are not easily taken up by plant roots the problem of bioavailability is much less important. However, the biodegradation and formation of metabolites has to be considered.