The Automatic Methods Group Newsletter

s of papers presented At-plant gas chromatographic analysis Malcolm Cooper and John Green BP Chemicals, Hull Of the several approaches to process analysis, at-plant analysis is proving to offer a number of significant advantages. Such systems involve placing analytical equipment adjacent to plant operations such that it can be used by operations staff as and when needed. These developments have proved possible as a result of the advent of more reliable and flexibly programmable gas chromatographic systems. Consequently a gas chromatograph with autosampler can be programmed using a PC based control system to specify choice of GC method and calibration protocol. Operation of the analyser involves placing vials in the autosampler tray followed by pressing a single button. Different methods are accessed by selecting the position for the sample vial in the autosampler tray. Results are output to a printer or to a LIMS. Operator intervention is reduced to a minimum whilst incorporating procedures to satisfy the varied requirements. Automatic system flushing allows analyses of crude and pure streams to be carried out on a single system, and check-samples ensure the integrity of the analyses. Examples of the use of laboratory gas chromatographic equipment were described in at-plant situations together with a discussion of the advantages realized by such an approach. Some elements of on-line analysis J. R. P. Clarke Department of Instrumentation & Analytical Science, UMIST, Manchester The need to survive leads to our requirement for clean air and water, good agriculture and food, health, energy and raw materials, adequate shelter, tools, security and transport. So a recent estimate that Western Europe spends 3% of its Gross Domestic Product on chemical measurements may not come as too great a surprise. Analytical measurements are required in order to provide quantitative and qualitative information about chemicals. This information is needed in order that decisions can be made, for example, to control or optimize industrial products or plant, for peoples’ health or safety and for the environment. Analytical measurements are based upon an interacting three part system comprising: (1) Sampling. (2) Transduction of the energy used for the measurement to a (normally) electrical signal. (3) Signal processing, to convert data into presentable information. Before designing an on-line analysis system it is necessary to agree the end-user’s aims. On discussion these may 0142-0453/96 $12.00 (C) 1996 Taylor & Francis Ltd 187