Test kits for water analysis
In this course we step outside the laboratory to look at some examples of analytical procedures being carried out in the field using commercial test kits.
Having quick tests that provide results on-site has extended the options available to the analyst. The methods used are chemical or microbiological in nature, and, thanks to advances in microelectronics, portable versions of standard laboratory instrumentation are commercially available.
But this doesn't mean this subject is new; the natural philosopher and military leader Pliny the Elder (23-79AD) described how the Romans used papyrus soaked in an extract from galls (small lumps produced when insects bore into wood) to detect iron in vinegar (Jungreis, 1997).
This was an early version of the spot test, which, in its simplest form, involves mixing a drop of an unknown substance with a drop of reagent, on some form of supporting medium (e.g. paper) and making an observation such as a colour change, effervescence or precipitation (or even noting a characteristic smell). Tests like this are, for many of us, reminiscent of our earliest introduction to chemistry. Two examples are shown in the video clips, Video 1 Test for carbonate and Video 2 Test for starch.
The portable kits we're looking at in this course are in many ways natural extensions of these tests. Thanks to the technical ingenuity of a number of specialist manufacturers, kits are available for such diverse applications as water testing, food and beverage analysis, clinical measurements, air quality monitoring and forensics.
However, the main focus of this course is on kits for water quality testing; we'll be looking at the construction of the portable apparatus and the underlying chemical principles and some of the practicalities of carrying out both sampling and analysis in the field.
In this course we will be looking at techniques that include wet chemical methods, molecular spectroscopy and electrochemistry. You are not expected to have studied these before; any relevant background theory will be included here.
This OpenLearn course provides a sample of level 2 study in