A new laser method for cleaning micropalaeontological specimens
A new laser method for cleaning micropalaeontological specimens
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一种清洁微型古生物标本的新激光方法
DOI：
10.1144/jm.23.2.165
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发表时间：
2004
影响因子：
2
通讯作者：
A. S. Henderson
中科院分区：
文献类型：
--
作者：
C. Miller;L. Cornish;C. Jones;C. Jones;A. S. Henderson
Q开关Nd：YAG（钕钇铝石榴石）红外激光器可用于微古生物标本的清洗，特别是用于扫描电镜研究的金钯涂层标本。激光处理前和激光处理后的未涂覆标本的变压SEM图像显示，激光不会对由磷酸盐，二氧化硅或方解石组成的微古生物标本在一些壁结构形式的不利影响。激光对样品的纹理表面没有影响，但会使用于将样品固定在短柱上的水溶性固定胶剥落和起皱。粘性碳片（参考琼脂科学）被认为是最好的安装介质，在处理过程中保持标本的位置，但微化石容易成为分离的过程中，如果没有牢固地连接。激光清洗与使用氰化钠去除金的传统方法相比具有许多优点，氰化钠是有毒的，缓慢的，并且由于钯在试剂中的不溶性而不能有效地去除金-钯涂层。这种激光去除方法有可能从样品中去除基质以及其他类型的涂层和封固介质，包括铝，碳和蜡。安全去除涂层可从镀有金钯的博物馆微型古生物标本中释放出重要的科学信息。
A Q-Switched Nd: YAG (neodymium yttrium aluminium garnet) infrared laser can be used to clean micropalaeontological specimens, particularly those coated in gold–palladium for SEM studies. Variable pressure SEM images taken of uncoated specimens before and after laser treatment show that the laser does not have a detrimental affect on micropalaeontological specimens composed of phosphate, silica or calcite in a number of wall structural forms. The laser has no effect on the textural surface of the specimen but flakes and crinkles water-soluble mounting glues used to fix specimens to the stub. Sticky carbon tabs (Reference Agar Scientific) were found to be the best mounting medium for holding specimens in place during treatment but microfossils were prone to become detached during the process if not attached firmly. Laser cleaning has a number of advantages over traditional methods of gold removal using sodium cyanide, which is toxic, slow and does not effectively remove gold–palladium coatings due to the insolubility of palladium in the reagent. This laser removal method has potential for removing matrix from specimens as well as other types of coating and mounting media including aluminium, carbon and wax. Safe removal of coatings releases important scientific information from gold–palladium coated museum micropalaeontological specimens.