Microscopy is a very useful tool, which can be applied to many situations; it enables the general characteristics of objects such as size, shape, composition and structure to be analysed. Once these features are known, they can be useful parameters to characterize the material, behaviour, chemical properties and history of a sample.
Looks
Although this is a vague description, which in theory requires no explanation, it means different things to different people. In general we will consider it to be an amalgamation of many characteristics such as; size, shape, composition and the relationship between structural elements. All of these aspects are what make an object recognizable and unique. It is important to be able to identify what is present, and many objects are commonly characterized and identified by their overall appearance. Classifying a sample may in itself be sufficient to solve a problem.
Size
One of the fundamental parameters that microscopy enables you to measure, is the size of an object. Most objects commonly examined range in size from centimetres to micrometres or even nanometres. All these different sized objects can be accurately measured. The size of a particle may affect some of its fundamental properties and behaviour. For example considering particles that could be respired: if the particle are too large and heavy then it may not be airborne long enough to travel into a lung, if they are small and light they may enter the lung but not stay, but if it is of the right dimensions and weight it may enter and stay within the lung and cause damage.
Shape
Another parameter that is significant in characterizing properties of objects is shape, as the particle shape changes, so will its behaviour. A simple example of this would be, a flat talc or graphite particle can behave as a lubricant, whereas a quartz particle with its angularity and hardness will be an effective abrasive. Another example of the importance of shape would be the roughness of a surface; a rough surface would have a far greater surface area and hence greater chemical reactivity.
Composition
This characteristic is immediately useful in understanding a problem, and answering the question “what is it made of” will often immediately solve the problem. Another question encompassed by this is, what elements are present within the sample, for example the question may be is there heavy metal contamination present. Element composition on the micro scale can be detected down to approximately 0.1 to 0.5 weight percent concentrations depending on the element and the matrix which it is within.
Relationships
Knowing the relationships between objects can be of great importance, as how one component relates to another may be critical to how a system functions. This aspect of microanalysis can often only be done by microscopic techniques, as a bulk analysis, by their very nature gives averages. The common question for this category is “is A associated with B”, or waht is a associated with. Some example would be; does the micro flora grow on the surface of a root, or does it invade the contents, does the cell contain Mn internally or is it external, where are the heavy metals located on the surface of an aggregate or internallyas, and many more questions.
All Rights Reserved.
No portion may be copied or reproduce without the written permission of SGMCC Enterprises.