红花对土壤矿质元素的吸收和积累

采用电感耦合等离子体原子发射光谱法(ICP-AES)检测红花不同部位和时期以及栽培土壤中K、Ca、Na、Mg、Fe、Cu、Zn、Mn、Cr、Cd、Pb、Ba、Ni和Al元素的含量。结果表明:红花各部位矿质元素含量差异明显。在红花各不同部位中K、Fe、Zn元素在幼苗中含量最高,Ca、Mg元素在成熟叶中含量最高,Cu元素在种子中含量最高;而K和Ca元素在种子中含量最低,Mg、Fe、Cu和Zn元素分别在花、茎、成熟叶和茎中含量最低。红花的幼苗和花对K元素吸收积累明显,幼苗和种子对Cu元素吸收积累明显,Ca元素在成熟叶中积累较多,相应元素含量远比土壤中相应的元素含量高。红花对土壤不同矿质元素的吸收利用差异较大,在长期栽培红花的土壤中应注意对吸收利用多的元素结合施肥进行补充。     

高山森林林窗对苔藓及土壤微量元素含量的影响

苔藓植物和土壤在森林元素循环过程中具有重要作用,其元素含量特征可能受林窗和生长基质的影响,但有关不同林窗位置对苔藓和土壤微量元素含量影响的研究尚未见报道。为理解林窗更新对森林苔藓和土壤微量元素含量及分布特征的影响,于2016年10月,调查研究了在川西高山岷江冷杉(Abies faxoniana)原始林林下、林缘、林窗和旷地中地表苔藓和石生苔藓Na、Zn、Mg、Mn、Ca、Fe元素含量以及对应土壤有机层和矿质土壤层的元素含量。结果表明:川西高山森林地表苔藓与石生苔藓的Na、Zn、Mg、Fe、Ca含量差异不显著,地表苔藓的Mn元素含量显著高于石生苔藓;土壤有机层的Zn、Mg、Mn和Ca元素含量显著高于矿质土壤层,但Fe元素含量则相反,Na元素含量差异不显著。林窗位置对地表苔藓和石生苔藓Na、Zn、Ca和Fe元素含量具有相似的影响,均以林窗和旷地相对较高;石生苔藓与地表苔藓的Mn含量对林窗的响应存在差异,石生苔藓的Mn含量以林下最高,而地表苔藓则以林窗中心最高。但是,林窗对苔藓植物Mg元素含量的影响不显著。森林林窗位置对土壤有机层和矿质土壤层微量元素含量具有相似的影响。Na元素含量以旷地土壤最高,而Zn、Mn、Ca和Fe含量以林窗中心的土壤最高;除元素Na,所有微量元素均以林缘的土壤最低。此外,地表苔藓的Na、Zn、Mn和Ca含量显著高于土壤,而土壤中的Fe含量显著高于苔藓植物;苔藓中Ca和Mn元素含量与土壤的Ca和Mn元素含量呈显著正相关。可见,高山森林林窗更新过程在不同程度上影响了森林地表苔藓和土壤对微量元素的吸存特征,为进一步了解林窗和苔藓植物在高山森林生态系统物质循环中的作用提供了新的角度。     

珍稀濒危植物矮牡丹体内矿质元素的研究

采用原子吸收分光光度法测定了矮牡丹体内的10种矿质元素,即K、Mg、Mn、Fe、Ni、Zn、Cu、Cd、Cr、Pb。分析了矿质元素在矮牡丹体内的分布规律及矮牡丹对各种元素的富集能力。结果表明:在不同器官中的矿质元素含量有显著差异, K、Mg、Mn、Ni、Cd、Cr、Pb以叶中为高, Fe、Zn、Cu分别以根、茎、叶柄中含量最高;大多数元素在叶柄中含量最低。矮牡丹对K、Mg、Mn、Fe、Zn有较强的吸收富集能力,一般叶的富集系数较其它器官为高。元素间相关分析表明:Zn、Cd、Cr、Pb、Mn、Fe、Ni、Cu之间有显著的相关性, K、Mg之间的相关性显著。此外,土壤与植物体内元素含量表现出显著的相关性。     

江苏东山山地枇杷果实品质与果园土壤、叶片和果实矿质元素的关系

以江苏省苏州吴中区山地种植的24个枇杷果园的‘白玉’枇杷为研究对象,采用典型相关分析法研究土壤、叶片和果实矿质元素间及其与果实品质指标的相关性,应用多元线性回归分析法筛选影响枇杷果实品质的土壤、叶片和果实的主要矿质元素和影响叶片矿质元素的主要土壤矿质养分因子,为改善枇杷果实品质的果园营养管理技术提供理论参考依据。结果表明:(1)枇杷果实品质指标在不同果园间存在较大差异。(2)枇杷果实品质主要受其叶片和果实矿质元素含量影响,其中:枇杷单果质量与叶片中N含量呈显著正相关,与果实中N含量呈显著负相关;可溶性固形物含量与叶片中N和Mg元素含量呈极显著正相关,与果实中P、Mn元素含量呈极显著正相关,与果实中Ca、Mg元素含量呈极显著负相关;可滴定酸含量与叶片中N和Zn元素含量呈显著负相关,与果实中N、Mn元素含量呈显著负相关,与果实中Ca元素含量呈显著正相关。(3)果实品质指标与土壤矿质养分含量的相关性较弱,土壤矿质养分主要通过影响叶片矿质元素含量,进而间接影响果实品质,其中土壤中P、K、Ca、Mn、Cu元素对叶片中矿质元素含量影响较大。研究认为,提高土壤中P、K、Zn含量并减少土壤Ca含量是东山山地枇杷果园土壤管理的关键技术途径;提高叶片中N含量以及果实中N、P、Mn含量和减少果实中Ca、Mg含量是改善东山山地枇杷果实品质的关键措施。     

ICP-AES测定广西巴豆不同部位中的十种微量元素

高压密封消化罐消解法将晒干的广西巴豆的根、茎、叶、种子壳及种子进行消解,ICP-AES同时测定其中K、Cu、Fe、Zn、Ca、Mg、Mn、Al、Sr、Na元素的含量,该方法的加标回收率在90.2%～114%之间,RSD<5.57%,测定结果符合分析要求。结果显示,Mn、Mg、Ca在巴豆叶中含量最高,种子中则富含Zn、Cu、K、Na,在种子壳中Sr的含量最高,根中含量最高的是Al,而K、Cu、Fe、Zn、Ca、Mg、Mn、Al、Sr、Na十种元素在茎中分布均匀。     

新疆绿洲农田土壤-棉花系统9种矿质元素生物循环特征

在新疆绿洲区,对不同连作棉田土壤中9种矿质元素含量、棉花植株的吸收和富集特性以及棉田养分收支量等进行分析,研究了农田土壤-棉花系统矿质元素的生物循环特征。结果表明:棉田土壤中微量元素和大量元素均有一定程度的贫化趋势,以Mo的耗竭最为严重。棉株不同器官累积矿质元素的能力有明显差异,叶片中Ca、Mg和Mn的含量较高,根、茎中K、Na、Fe、Mo含量较高,棉籽中Zn和Cu含量最高;不同产品器官对矿质元素的吸收和富集能力不同,秸秆为:MoKMgCaCuZnNaMnFe,纤维:MoKMgZnCuCaNaMnFe,棉籽:MoZnKMgCuCaMnNaFe。棉花对Mo的吸收能力最强,长期连作导致土壤中Mo耗竭较为严重;随籽棉的收获,从棉田移出Zn、Cu的比例和数量较高,大量元素中移出Mg、K较多;棉花对Mn、Fe、Ca、Na的吸收量虽然较多,然而大部分富集在秸秆中,随着棉花秸秆的还田作用,将归还于耕作层并有大量富集,消耗量不大。新疆棉花长期单一种植,应重点补充Mo、Zn和Cu微量元素肥料,酌情补充Mg、K等大量元素肥料。棉田Ca、Na含量较新疆土壤背景低,预示着棉田土壤在向着脱盐碱方向发展,然而两元素在秸秆中的比例较高,因此棉花长期连作农田,应注意防止耕作层土壤向次生盐碱化方向发展。     

湘西地区木通果实微量元素的测定

采用马弗炉干法灰化消化样品,火馅原子吸收法连续测定白木通Akebia trifoliata var.australis (Cieli._Kehd、三叶木通A.trifoliata(Thumb.)Koidz、木通A.quinata Decne.果实中微量金属元素,检测出K,Ca,Na,Mg,Fe,Zn,Mn,Cu等8种元素含量。3种植物果实中K,Ca,Mg含量较高(＞0．1000mg/g),其中K元素远高于其他元素,Na,Cu含量较低(＜0．0100mg/g)。Fe,Zn,Mn的含量处于中等水平。白木通果实中K,Me,Zn,Mn 4种矿质元素高于三叶木通和木通。木通果实中Ca,Fe两种元素稍高于白木通、三叶木通。Na,Cu两种微量元素在3种果实中含量基本相拟。     

福州酸雨区次生林中台湾相思与银合欢叶片的12种元素含量

在酸雨区,研究叶片元素浓度变化规律对于理解树种选择与重建亚热带森林具有重要意义。在中亚热带丘陵次生林的酸雨区内,测定两个优势树种——台湾相思树(Acacia confusa)、银合欢(Leucaena glauca)的叶片元素(N、P、S、K、Ca、Na、Mg、Fe、Mn、Cu、Zn和Al)含量,并探讨其可能遭受酸雨的影响。结果表明,两树种叶片营养元素含量均表现为N > K > Ca > S > P > Mg > Na,重金属元素表现为Fe > Al > Cu。两树种叶片的P、Ca、Mg、Na、Mn和Cu含量差异极显著,Zn含量差异显著。受频繁酸雨影响,台湾相思(3.42 g/kg)和银合欢(2.70 g/kg)的S含量明显高于中国陆生被子植物叶片的平均值((1.66±3.06) g/kg),Na含量低于S含量,也明显低于中国陆生被子植物叶片Na含量的平均值((2.48±5.45)g/kg),表明研究区域植物叶片的Na元素的特异性,酸雨加速土壤酸化导致土壤Na含量低可能是一个原因。由N/P、Ca/Al摩尔比值的大小可得出,台湾相思为P制约型树种,虽然其Al含量并未超出正常范围值,但其Ca/Al摩尔比值小于12.5,表明存在Al的危害风险;而银合欢属N制约型树种,并未受到Al的危害,更适应研究区生长环境。若仅从叶片元素含量分析,该区域的台湾相思和银合欢受到Fe危害风险,且存在更大的Cu和Zn危害风险,银合欢的Zn、Cu元素累积量大于台湾相思,所以可以认为银合欢的抗性强于台湾相思,可能更适应于酸雨区域生长。     

江苏不同产地‘白玉’枇杷果实品质与果实和土壤中矿质元素含量的相关性分析

对江苏高淳、溧阳、镇江和苏州4个产地‘白玉’枇杷(Eriobotrya japonica‘Baiyu’)果实的品质指标和矿质元素含量以及土壤中矿质元素含量进行测定,并据此分析果实和土壤中矿质元素含量与果实品质的相关性。结果表明:不同产地‘白玉’枇杷果实的品质指标及果实和土壤中矿质元素含量均有不同程度差异。溧阳和苏州产果实的单果质量、横径、纵径、可滴定酸含量、含水量和果肉厚度均极显著或显著高于高淳和镇江产果实,但其可溶性固形物含量和固酸比均极显著低于后二者。果实中N、P、K、Mg、Mn和Zn含量均以苏州产果实最高,Ca含量以镇江产果实最高,Na含量以溧阳产果实最高,Fe和Cu含量均以高淳产果实最高;土壤中N、P、K、Ca、Cu和Zn含量均以苏州产地最高,Mg含量以镇江产地最高,Na和Fe含量均以高淳产地最高,Mn含量以镇江和苏州产地最高。相关性分析结果表明:在果实中,除Ca和Fe含量外,其他矿质元素含量与多数果实品质指标均呈极显著或显著相关性;其中,N、P、K和Mn含量与单果质量、横径、种子质量和果肉厚度均呈极显著或显著正相关;N、P、K、Mg和Na含量与可溶性固形物含量和固酸比均呈极显著或显著负相关,与可滴定酸含量和含水量均呈极显著或显著正相关;但Cu含量却与单果质量、横径、果肉厚度、可食率、可滴定酸含量和含水量呈极显著或显著负相关,与可溶性固形物含量和固酸比分别呈显著和极显著正相关。在土壤中,Ca和Cu含量与果实品质指标均无显著相关性,K和Zn含量与固酸比分别呈极显著的正相关和负相关,Mg和Fe含量与多数果实品质指标均呈负相关,且与其中部分果实品质指标呈极显著或显著相关;此外,N含量与单果质量、果肉厚度、可滴定酸含量和含水量,P含量与横径、种子质量、果肉厚度和可滴定酸含量呈显著或极显著正相关。研究结果表明:溧阳和苏州产‘白玉’枇杷果实较大,但可溶性固形物含量较低;果实中N、P、K、Mg和Cu含量以及土壤中N、Mg、Fe、P和Na含量对果实品质均有较大影响。此外,依据研究结果,对实际生产中各元素的施用量提出建议。     

增温对长白山苔原植物叶片和土壤矿质元素含量的影响

温度变化会影响植物对养分的吸收以及自身养分含量变化,尤其对长期处于低温条件下的苔原植物。采用开顶箱增温法,研究了1个生长季增温对长白山苔原3种代表植物——牛皮杜鹃(Rhododendron aureum Pall)、笃斯越桔(Vaccinium uliginosum)和东亚仙女木(Dryas octopetala var.asiatica)叶片及土壤矿质元素钾(K)、铝(Al)、铜(Cu)、铁(Fe)、镁(Mg)、锰(Mn)、锌(Zn)和钙(Ga)含量的影响。结果表明:1)增温明显改变了土壤矿质元素含量,使土壤Fe、Al和K含量分别增加0.44%、2.76%和4.88%,而Cu、Mg、Mn、Zn和Ga含量分别降低2.63%、5.07%、7.46%、21.95%和15.60%;2)整个生长季,增温使牛皮杜鹃叶K含量增加8.17%,且具有明显的月变化,其叶Mg和Mn含量也分别比对照组高66.39%和14.73%;3)与对照相比,增温使笃斯越桔叶K、Al和Zn含量分别增加15.24%、5.45%和87.45%,生长季不同月份,其叶K、Al、Mg、Mn、Zn和Ga含量差异明显;4)增温并没有明显改变东亚仙女木叶片各矿质元素含量,但其叶K、Cu和Ga含量具有明显月波动。因此,不同物种矿质元素含量变化对增温的响应方式不同,增温对苔原植物的影响也存在一定的物种差异性。     

Mineral Elements in Root of Wild Saposhnikovia divaricata and Its Rhizosphere Soil

Mineral elements are important components of medicinal herbs, and their concentrations are affected by many factors. In this study, Ca, Mg, Na, K, Fe, Mn, Cu, and Zn concentrations in wild Saposhnikovia divaricata and its rhizosphere soil collected from seven locations at two different times in China were measured, and influences of rhizosphere soil on those minerals in plant were evaluated. The results showed that mean concentrations of eight minerals in plant samples decreased in the order: Ca > Mg > Na > K > Fe > Zn > Mn > Cu, and those in the soil samples followed the following order: Na > Fe > Ca > K > Mg > Mn > Zn > Cu. Mean concentrations of Ca, Na, Mg, and K in plants were higher than those in soils, while higher mean concentrations of the other four minerals were found in soils. It was found that there was a positive correlation of Mg, Na, and Cu concentrations in the plant with those in the soil respectively, but a negative correlation of Mn concentration in plant with that in the soil. Except Ca, K, and Mn, the other five minerals in plant were all directly affected by one or more chemical compositions of soil. The results also indicate that pH value and concentrations of total nitrogen, Mg, Mn, and Cu in soil had significant correlations with multimineral elements in plant. In a word, mineral elements uptake of S. divaricata can be changed by adjusting the soil fertility levels to meet the need of appropriate quality control of S. divaricata.     

Accumulation of Minerals by Leccinum scabrum from Two Large Forested Areas in Central Europe: Notecka Wilderness and Tuchola Forest (Pinewoods)

Leccinum scabrum sporocarps and associated topsoils from two areas in Poland have been characterized for contents and bioconcentration potential of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn. Topsoil and fruitbody element composition varied between the two study sites, most likely as a result of local soil geochemistry. Element content of the labile fraction in topsoil from both sites followed the ‘pseudo‐total’ fraction and median values (mg kg^?1 dry matter) were: K 380 and 340, Mg 760 and 840, P 1100 and 920, Al 3800 and 8100, Ag 0.31 and 0.28, Ba 28 and 37, Ca 920 and 790, Cd 0.23 and 0.23, Co 2.0 and 1.7, Cu 3.2 and 3.6, Fe 2800 and 6300, Mn 280 and 180, Na 99 and 110, Ni 7.8 and 8.8, Pb 12 and 18, Rb 1.3 and 2.1, Sr 4.8 and 4.0 and Zn 22 and 19, respectively. Only for some elements such as K, Mg, Al, Ag, Ca, Co, Mn, Na, Ni, Sr and Zn we found concentration differences between the two study sites for the caps of sporocarps. With the exception of Al, Mn, Na and Pb, stipes showed a similar tendency. Caps had a higher concentration of K, Rb, P, Mg, Al, Ag, Cu, Fe, Zn, Cd, Pb and Ni compared to stipes, while Na, Ba and Sr contents were higher in stipes. The comparison of soil and fruitbody concentrations indicates that L. scabrum bioconcentrate some elements while others are bioexcluded.     

气象因子和矿质元素对虎杖根茎白藜芦醇含量的影响

对全年各月虎杖材料中白藜芦醇含量,及其Ca、Cu、Fe、K、Mg、Na、Zn 8种矿质元素积累进行检测,结合气象因子动态变化,采用主成分分析法,研究了不同季节虎杖白藜芦醇含量动态变化与其矿质元素、气象因子动态变化的关系．结果表明,Cu与Fe,Mg与K、Zn,Ca与月日照时数,K与Zn相关系数分别为0．812、0．871、0．793、0．602、0．729,呈极显著正相关;Cu、Mn与月平均气温,Fe与K相关系数分别为-0．738、-0．712、-0．766,呈极显著负相关;Cu与白藜芦醇含量呈显著负相关．找出了影响虎杖白藜芦醇含量动态变化的5个主成分,其中“酶促反应促进性矿质营养因子”,“高温、强照射气象因子”的贡献率分别为35．539％、33．358％,合计为68．897％,二者对不同季节虎杖白藜芦醇的变异贡献率最大．同时进行白藜芦醇含量的动态变化与主成分的多元相关、回归分析,建立了回归方程。     

Studies on the Characteristic of Element Contents in the Dominant Plant Species of the Three gorges Region in China

The characteristics of the contents of 20 elements (Al, Fe, Mn, Ca, Mg, K, S, Si, P, Cd, Cu, Zn, Ti, Ni, Sr, Mo, Na, B, Cr, V) in 16 plant species collected from the Three Gorges Region in China were investigated. The average contents of Ca, K and Mg were higher than 1 000 μg·g-1, that of Al, P, Si, Fe, S and Mn ranged between 100—1 000 μg·g-1 and Ti, Cu, Ni, Cr, Mo, Cd and V were less than 10 μg·g- 1. The level of Na content was less than that of the reported. The main character of the element contents was of the Ca> K type. The contents of P, S, Ca and K in different plant samples showed a normal distribution pattern, while Al and Mn showed a elements lognormal distribution pattern. Plant species differed greatly in the element contents. On analyzing the coefficient of variation (C. V., % ), Al, Mn, Mg, Ni, Sr and Fe had higher C.V., while the C.V. of K, S, P, Cr, Cd and Cu was less than 60%, and Cu had the lowest C.V. The correlations between Al and Fe, Al and Ti, Al and Cr, A1 and V, Cd and Sr, Cd and Mo, Fe and V, Zn and Cr, Ni and Sr, Mg and Ni, Mo and Sr, Ca and Sr, Cr and Mo, Na and Mg, Na and P, P and S were statistically significant in different plant species. The classification of the 16 plant species and 20 dements by two-way indicator species analysis (TWINSPAN) method may suggest the difference in dement contents of the different plant species.     

Determination of the mineral elements in the pollen of some Gymnospermae

In this work the principal elements (K, Ca, Fe, Mg, Cu, Zn, Mn, Na) constituting the mineral component of the pollen in some Gymnospermae, have been determined. This type of investigation has few matches in literature despite the importance some mineral elements have in germinating the pollen granule. The pollen samples, appropriately treated, were analysed in atomic absorption spectrophotometry and biometrically characterized under the optical microscope. Examination of the analytical data allows verification of the great influence deriving from soil characteristics and, within the families, a specific role of the type. The morphobiometric parameters show that a link exists between small and medium granules and with thin walls and minimum concentration values of Na, Fe, Cu, Zn and Mn.     

Variations in the Mineral Composition of Herbarium Plant Species Collected During the Last Three Centuries

Mineral content (dry weight basis) was determined for herbariumspecimens of 12 C₃ plants (trees, shrubs and herbs) collectedduring the last 250 years in N.E. Spain. Present values of Al,Ca, Cu, Sr, Fe, P, Mg, Mn, K, Na, S, and Zn were always lowerthan in any other period of the last three centuries. Only oneC₄ plant was analysed. It presented a similar pattern to theC₃ plants. These results are in accordance with experimentalresults that have shown that the mineral content of plants grownin elevated CO₂ is generally lowered. Increased atmosphericCO₂ and other anthropogenic environmental changes are suggestedas possible causes of the changes in mineral content. Key words: Leaf mineral content, Al, Ca, Cu, Sr, Fe, P, Mg, Mn, K, Na, S, Zn, herbaria, last three centuries     

Geochemistry of recent marine sediments in the Bardawil lagoon,northern Sinai,Egypt

The concentrations of major (Al, Fe, Mg, Ti, K and Na) and minor (Ba, Sr, V, Cu, Mn, Cr, Ni, Zn, Pb and Mo) elements as well as carbonate, organic carbon and total nitrogen have been determined in surface sediments collected at 12 stations from the Bardawil lagoon. The aim of the study was to characterize the geochemistry of the sediments in three different environments, the lagoon, the salt pans and the inlet between the lagoon and the Mediterranean Sea. Higher CaCO₃ percentage (53.5–70.5%) were found in the salt pans where biogenic calcareous components and carbonate rock fragments were found in sufficient quantities in the sediment fractions. Based on high C/N ratios, the organic carbon fraction of the Bardawil lagoon surface sediments is clearly dominated by terrigenous material. The distribution of Al, Fe, Mg and Ti are essentially controlled by the mineralogy of the sediments. The ratios of Ba, Sr, Cu, Mn, Pb and Mo to Al are all high in the salt pans and reflect changes in mineralogy and sediment texture.     

Medical application of laser-induced breakdown spectroscopy (LIBS) for assessment of trace element and mineral in biosamples: Laboratory and clinical validity of the method

BackgroundBiomedical application is based on the use of LIBS-derived data on chemical contents of tissues in diagnosis of diseases, forensic investigation, as well as a mechanism for providing online feedback for laser surgery. Although LIBS has certain advantages, the issue of correlation of LIBS-derived data on chemical element content in different human and animal tissues with other methods, and especially ICP-MS, remains pertinent. The objective of the present review was to discuss the application of laser-induced breakdown spectroscopy (LIBS) for elemental analysis of human biosamples or tissues from experimental models of human diseases. Methods. A systematic search in the PubMed-Medline, Scopus, and Google Scholar databases using the terms laser-induced breakdown spectroscopy, LIBS, metals, trace elements, minerals, and names of particular chemical elements was performed up through 25 February, 2023. Of all extracted studies only those dealing with human subjects, human tissues, in vivo animal and in vitro cell line models of human diseases were reviewed in detail. Results. The majority of studies revealed a wide number of metals and metalloids in solid tissues including teeth (As, Ag, Ca, Cd, Cr, Cu, Fe, Hg, Mg, Ni, P, Pb, Sn, Sr, Ti, and Zn), bones (Al, Ba, Ca, Cd, Cr, K, Mg, Na, Pb, Sr), and nails (Al, As, Ca, Fe, K, Mg, Na, P, Pb, Si, Sr, Ti, Zn). At the same time, LIBS was also used for estimation of trace element and mineral content in hair (Ca, Cu, Fe, K, Mg, Na, Zn), blood (Al, Ca, Co, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Si, Sn, Zn), cancer tissues (Ca, Cu, Fe, Mg, K, Na, Zn) and other tissues. Single studies revealed satisfactory correspondence between quantitative LIBS and ICP-OES/MS data on the level of As (81–93 %), Pb (94–98 %), Cd (50–94 %) in teeth, Cu (97–105 %), Fe (117 %), Zn (88–117 %) in hair, Ca (97–99 %), Zn (90–95 %), and Pb (61–82 %) in kidney stones. LIBS also estimated specific patterns of trace element and mineral content associated with multiple pathologies, including caries, cancer, skin disorders, and other systemic diseases including diabetes mellitus type 2, osteoporosis, hypothyroidism, etc. Data obtained from in situ tissue LIBS analysis were profitably used for discrimination between tissue types. Conclusions. Taken together, the existing data demonstrate the applicability of LIBS for medical studies, although further increase in its sensitivity, calibration range, cross-validation, and quality control is required.     

Influence of roots and climate on mineral and trace element storage and flux in tropical mangrove soils

The storage and flux of various mineral and trace elements in soils (0–30cm depth) were examined in relation to monsoonal rains and fine root biomass in four mangrove forests of different age and type in southern Thailand. The onset of the wet SW monsoon resulted in the percolation and dilution of porewater solutes by rainwater and by less saline tidal water, as indicated by shifts in Eh, pH and porewater SO₄/Cl ratios. This is contrary to temperate intertidal environments where seasonal patterns of porewater constituents, and biological and biogeochemical activities, are strongly cued to temperature. Fluxes across the soil–water interface were most often not statistically significant. Concentration of dissolved porewater metals were dominated by Fe, Mn, Al, Mo and Zn. The decreasing order of solid-phase element inventories in these soils, on average, was: Al, S, Fe, Na, Mg, K, Ca, N, P, Mn, V, Zn, Cr, Ni, As, Co, Cu, Pb, Mo, Cd and Hg. There were no gradients in concentrations of dissolved or solid-phase elements with increasing soil depth. This phenomenon was attributed to physical and biological processes, including the presence and activities of roots and tidal recharge of soil water. Fine dead roots were storage sites for most mineral and trace elements, as some elements in roots composed a significant fraction (5%) of the total soil pool. Analysis of S and Fe concentration differences between live and dead roots suggested extensive formation of pyrite associated with dead roots; correlation analysis suggested that trace metals coprecipitated with pyrite. An analysis of inventories and release/uptake rates indicate turnover of the N, P, Na and Ca soil pools equivalent to other tropical forests; turnover was slow (decades to centuries) for S, Fe, K and trace elements. Our results indicate that mineral and trace element cycling in these soils are characterized by net storage, with net accumulation of most elements much greater than uptake and release by tree roots.