Batch sampling and wet chemical methods of gas analysis

Much of this book deals with sophisticated optical and electronic instruments for continuous monitoring of gaseous pollutants. These have increasingly replaced traditional methods involving batch sampling and wet chemical methods of analysis. However, there are some species where continuous analysers are not available. There are also applications where results are only required periodically and therefore the additional expense of a continuous monitor is not justified. There are many industrial sites with well-equipped chemical laboratories which are quite capable of undertaking analyses of gases or liquids arising from a sampling programme relating to a flue gas or process gas stream. So there will continue to be situations where off-line analysis makes practical and economic good sense. More than this, batch sampling and subsequent analysis has been — and will continue to be — the basis of many reference test methods and for this reason, if for no other, they will continue to be used.