AAS测定巨大口蘑子实体及生长土壤微量元素

本文所述用原子吸收法测定巨大口蘑子实体及生长土壤微量元素，其结果是红河菌株和思茅菌株子实体的微量元素富集量有较大差异，生长土壤微量元素富集量与子实体中的微量元素富集量都有密切关系。该方法操作简便、分析快速，测定结果令人满意。     

原子吸收光谱法测定中药生地和熟地中3种微量元素的含量

目的:建立测定中药生地和熟地中微量元素的方法.方法:采用湿法消化法处理样品,用火焰原子吸收光谱法测定中药生地和熟地中微量元素的含量.结果:中药生地和熟地中含有Zn,Cu,Fe等微量元素;平均回收率为:Fe:102.1%,Zn:96.9%,Cu:101.1%,RSD为:Fe:3.8%,Zn:2.2%,Cu:3.4%.结论:中药生地和熟地中含有丰富的对人体有益的微量元素,该测定方法简便,精密度及重现性均较好.     

南瓜中铬的化学形态及其含量研究

对8个品种老熟南瓜中铬含量进行了测定,分析了铬的不同化学形态及分布。结果表明:不可溶态总铬(CrT1)占总铬含量的8.92％,可溶态总铬(CrTS)占总铬含量的91.08％,三价铬(Cr3+)占CrTS的91.25％,六价铬(Cr6+)占CrTS的8.75％,可溶态有机铬(CrO)占CrTS的4.03％;不同栽培种(中国南瓜和印度南瓜中的西洋南瓜)的铬含量高低无规律性,不同栽培品种之间铬含量差异明显。     

微波消解-原子吸收法检测鸡组织中的重金属含量

采用微波消解原子吸收法测定鸡组织样品中的铅、镉、铜、铬等元素的含量 ,结果表明 :①组织中Pb的含量心脏 >肝脏 >肌胃 >胸肌 >肾脏 >腿肌 >骨骼 ,超标率分别为1 0 0 .0 % ,96.87% ,96.87% ,87.50 % ,1 0 0 .0 % ,81 .2 5% ,0 %。②组织中Cd的含量肾脏 >骨骼>腿肌 >肝脏 >心脏 >肌胃 >胸肌 ,超标率分别为 6.2 5% ,0 ,3 .1 3 % ,0 % ,0 % ,0 % ,0 %。③组织中Cu的含量心脏 >肝脏 >肾脏 >骨骼 >肌胃 >胸肌 >腿肌 ,超标率分别为 1 2 .50 % ,1 5.63 % ,9.3 8% ,3 .1 3 % ,0 % ,0 % ,0 %。④组织中Cr的含量肾脏 >肝脏 >心脏 >胸肌 >腿肌>骨骼 >肌胃 ,超标率分别为 50 .0 0 % ,62 .70 % ,9.3 8% ,3 .1 3 % ,0 % ,0 % ,0 %。     

Effects of Extraction Conditions on the Content of Anthocyanins and Bioelements in Berry Fruit Extracts

Abstract

Two methods for extracting anthocyanins and bioelements [calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe)] from black chokeberry, black currant, strawberry, and bilberry fruits were compared in this study. Correlations between the content of anthocyanins and bioelements in fruit extracts were determined using method A [extraction with hydrochloric acid (HCl)] and method B [extraction with water (H₂O)]. Relationships between the content of anthocyanins and particular nutrients, as well as between Mg and Ca and between Zn and Fe, in fruit extracts obtained by method A and by method B were also established.

The mean content of anthocyanins and bioelements (Ca, Mg, Zn, Fe) was the highest in black chokeberry fruits, regardless of the extraction method used. Bilberry fruits had the lowest nutrient content, despite a high anthocyanin content. The mean content of anthocyanins and bioelements was higher in fruit extracts obtained by method A than method B. The coefficients used to recalculate method A into method B were anthocyanins, 5.1; Ca, 1.1; Mg, 1.2; and Zn, 2.2. The statistical analysis showed that the effect of a given extraction method on the content of anthocyanins and bioelements (except for Ca) in fruit extracts depended on fruit species. The correlations between the content of anthocyanins, Ca, Mg and Zn in fruit extracts obtained by method A were found to be positive and highly significant, in comparison with method B. There was no correlation between the content of anthocyanins and particular nutrients in fruit extracts obtained by method A and by method B. The Mg content of fruit extracts was highly significantly higher than the Ca content, irrespective of the extraction method applied.     

硝酸—高氯酸与王水回流法在AAS测定中的比较

王水迴流法消化污泥和土壤,较常规的王水消化法可多提取10%的重金属.本实验应用1:1的硝酸—高氯酸和铝制消化器对128个土壤样品镉、铬、铜、铅、锰、镍和锌7个元素进行了测定,并与王水迴流法所测数据进行了比较.统计结果表明,两种方法所得结果具有极显著的相关性,然而是截然不同的两组数据.除锌外,用硝酸—高氯酸法所得值明显高于王水迴流法,可在实验室广泛使用.在铬的测定中,钠、钾、镁、钙、锰、铝和铁做为潜在的干扰因素及不同火焰状况对测定的影响被加以探讨.结果表明,使用贫氧化亚氮—乙炔火焰不会产生正、负干扰.     

Comparison of Lead Extraction and Detection Procedures for Six Canadian Soils

The effects of acid digestion procedures and instrumentation on extracted lead (Pb) concentrations from several soils, including a mildly Pb-contaminated soil, were determined using a two-factor factorial experiment. The two factors were (i) digestion procedure [seven levels: U.S. EPA, AOAC (dry ashing), nitric acid (NA), three aqua regia procedures (AR1, AR2, and AR3), and hydrofluoric acid (HF)] and (ii) instrumentation [two levels: atomic absorption spectrometry (AAS) and inductively coupled plasma (ICP) spectroscopy]. The greatest Pb recovery was obtained when soils were digested with HF and analyzed by AAS. The results suggest that the AOAC procedure (a standard procedure for recovery of soil nutrients and trace elements in Canadian laboratories) and EPA procedure (a standard procedure in American laboratories) may underestimate Pb concentrations in some Atlantic Canadian soil types. The AAS procedure is more accurate than ICP for determining Pb concentrations in soil with a history of PbHAsO₄, at least for Atlantic Canadian soils.     

流动注射氢化物原子吸收光谱法测定食品中的痕量砷

研究了流动注射氢化物原子吸收光谱法测定食品中的痕量砷。样品经消解后,加入还原剂抗坏血酸和碘化钾,使五价的砷还原为三价砷,在酸性介质中三价砷和硼氢化钾反应形成砷化氢,随反应液由氮气载气带入气液分离器分离,而后加载于电热石英原子化器分解为原子态砷并进行测定。在最佳的分析条件下,获得较为满意的分析结果,相对标准偏差0.507%～3.350%,检出限0.18μg·L-1,加标回收率为92.6%～101.5%。     

SPATIAL DISTRIBUTION AND ACCUMULATION OF CALCIUM IN DIFFERENT TISSUES,DEVELOPING SPIKES AND SEEDS OF FINGER MILLET GENOTYPES

□ Total calcium (Ca) content in different tissues, developing spikes (S1, S2, S3 and S4 stages), and distribution sites in seeds of five finger millet genotypes, which were differed in total calcium content, were analyzed. Atomic absorption spectroscopy (AAS) revealed stage-dependent quantitative changes in calcium accumulation from low to high during different stages of developing spikes and also in different tissues and grains. Results of scanning electron microscopic (SEM) energy dispersive X-ray (EDX) analysis showed differential distributions of the calcium in seed components viz. seed coat, aleurone layer and endosperm. Highest calcium content was observed in aleurone layer followed by seed coat while lowest calcium was found in endosperm of all genotypes. Major differences were found amongst genotypes with regard to the calcium distribution in seed components. The differential regulation of transport machinery might be responsible for differential calcium ion delivery and spatial distribution in the seed. A clear understanding of differential accumulation, spatial distribution and the variation of calcium within finger millet genotypes/seeds could be exploited for breeding for their bio-fortification and development of calcium rich functional foods.