Seltzer Michaeld, Berry Kristinh
Naval Air Warfare Center Weapons Division, Code 4T4230D, 1900 N. Knox Road Stop 6303, China Lake, CA 93555-6106, USA.
Sci Total Environ. 2005 Mar 1;339(1-3):253-65. doi: 10.1016/j.scitotenv.2004.07.027.
The outer keratin layer (scute) of desert tortoise shells consists of incrementally grown laminae in which various bioaccumulated trace elements are sequestered during scute deposition. Laser ablation ICP-MS examination of laminae in scutes of dead tortoises revealed patterns of trace elemental distribution from which the chronology of elemental uptake can be inferred. These patterns may be of pathologic significance in the case of elemental toxicants such as arsenic, which has been linked to both shell and respiratory diseases. Laser ablation transects, performed along the lateral surfaces of sectioned scutes, offered the most successful means of avoiding exogenous contamination that was present on the scute exterior. Semiquantitative determination of elemental concentrations was achieved using sulfur, a keratin matrix element, as an internal standard. The results presented here highlight the potential of laser ablation ICP-MS as a diagnostic tool for investigating toxic element uptake as it pertains to tortoise morbidity and mortality.
沙漠陆龟龟壳的外层角质层（盾片）由逐渐生长的薄片组成，在盾片沉积过程中，各种生物累积的微量元素被隔离在其中。对死亡陆龟盾片中薄片进行激光烧蚀电感耦合等离子体质谱（ICP-MS）检测，揭示了微量元素分布模式，据此可推断元素摄取的时间顺序。对于像砷这样与龟壳和呼吸系统疾病都有关联的元素毒物而言，这些模式可能具有病理学意义。沿着切片盾片的侧面进行激光烧蚀横断面分析，是避免盾片外部存在的外源性污染的最有效方法。使用硫（一种角蛋白基质元素）作为内标，实现了元素浓度的半定量测定。此处呈现的结果凸显了激光烧蚀ICP-MS作为一种诊断工具的潜力，可用于研究与陆龟发病和死亡相关的有毒元素摄取情况。
