B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 1 Chemical Industry Purpose: To produce chemicals..... to the correct specification profitably without harm to the environment safely lawfully whilst protecting intellectual property Analytical Chemistry has its part to play.....

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 2 Good Results Fit for purpose Accurate Precise Qualitative / Quantitative Consistent Allow decisions to be made Provided in an appropriate form Provided on time Obtained at minimum cost & effort Retrievable /Traceable Validated Repeatable Reproducible

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 3 Industrial Functions Manufacture Research & Development Supplying the customer Health Safety and Environment

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 4 Industrial Research (Example) Example - conversion of butane into ethene Possible dehydrogenation reaction butane ethene + propene + butene Important parameters: –Conversion of butane into products –Selectivity of conversion to ethene Analytical requirements –accuracy  to ensure scale-up is valid –sensitivity  to detect low concentrations –flexibility  to identify unexpected products

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 5 Chemical Manufacture Analytical Requirements precision of measurement –monitors progress of reaction –detects process fluctuations accuracy less important frequency of analysis minimum cost & effort display of results/feedback protocols

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 6 Supplying the Customer Accuracy  ensures product is ‘in-spec’ Demonstrate validity  a recognised method Reproducibility  comparable result whoever carries out the analysis Consistent  same sample same result

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 7 Analytical Techniques & Product Purity High purity is expensive –More steps required in fractional crystallisation –Less take-off in distillation columns Better analytical techniques reduce the cost of obtaining high purity –Greater precision allows required purity to be targeted more closely

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 8 Analytical Confidence Limits All measurements have errors associated with them Quoted values should therefore be expressed with an associated confidence interval [X ± x units] To be assured that a sample conforms to a quoted specification limit an analytical value must be obtained for the sample that takes the confidence interval into account. Example: Technique gives value ± 1% Sample must be >97% pure Therefore technique must deliver a value of 98% to be confident of sample purity being >97% pure

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 9 Analytical Techniques & Cost of Quality Purity (%) Cost 100% 99%98%97%96% 95% 98.5% 98.1% Cost Saving due to Improved Analysis

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 10 Analytical Techniques and Asset Utilisation Chemical plant is expensive Maximum utilisation is desirable Analytical techniques help to maximise the utilisation –Reduce turnround times on batch operations –Increase throughput on continuous plant

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 11 Analytical Techniques and Asset Utilisation Batch Operations Reactant Concentration Time of Batch Operation Conversion Required Analytical technique 1Analytical technique 2 Improved Times at which batch can be terminated for required conversion Time saved

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 12 Analytical Techniques & Asset Utilisation Continuous Processes Throughput Required Purity Increased Throughput Purity of product required 99%98%97%96% Analytical technique 2 Analytical technique 1

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 13 Analytical Chemistry & Environmental Responsibilities Emissions to Air Emissions to Water Waste disposal - off-site Technical challenges –low concentrations in air/water/solids –sample collection times –sensitive techniques required for temporal resolution –samples containing contaminants

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 14 Corrosion Measurements Chemical Plant Maintenance –Regular shutdowns / unplanned shutdowns –Components replaced Corrosion /Production /Shutdown Frequency –Relationship between corrosion & process variables..... –higher productivity whilst maintaining plant integrity –lower frequency of shutdowns

B. Neidhart, W. Wegscheider (Eds.): Quality in Chemical Measurements © Springer-Verlag Berlin Heidelberg 2000 J. Green Why do we need Good results? 15 Valid Analytical Measurement Principles Analytical Measurements should be made to satisfy an agreed objective Analytical Methods should be made using methods and equipment which have been tested to ensure they are fit for purpose Staff making analytical measurements should be both qualified and competent to undertake the task There should be regular independent assessment of the technical performance of a laboratory Analytical measurements made in one location should be consistent with those made elsewhere Organisations making analytical measurements should have well defined quality control and quality assurance procedures.