The use and preparation of reliable reference materials that have traceability to international standards is key to laboratories realising their analytical performance targets. Standard operating procedures (SOP) used by analysts have improved precision in line with environmental, clinical, health and production demands. And now with instruments able to measure analytes in the ppm and ppb levels routinely there is a greater need for accuracy.
ISO Guide 17025 is taken as an audited measure of a company’s ability to offer robust analytical measurement that would stand-up to the scrutiny of its peers and offer traceability to international standards
However the fact that a company’s analytical procedures are well documented does not always offer the confidence that the analytical data generated by them is credible. Errors found usually relate to calculations, transcriptions and, more often, technique.
The fundamental demand on any analyst is showing when, how and what was done to achieve the result. Using equipment that can be seen as fit for purpose, and through recording traceability, allows the analyst to demonstrate that there is consistency and a quantifiable link between the measured result and that of the standard references.
To reduce the variance in performance of individuals following an identical analytical method, improvements in basic laboratory skills or adopting an innovative procedure that provides conclusive documentation may provide the means for the laboratories to achieve their analytical metrics.
When considering current laboratory procedure it is evident that in comparative studies the preparation and use of appropriate RMs appear to be the most significant variant in achieving proficiency. It is therefore surprising that the methods used in the preparation of standards have changed little since the Alchemists.
The time-consuming and cumbersome method of standards preparation using volumetric glassware may produce the precision a user requires but is not accurate or error free. And if results are required to be validated by a third party, what evidence could be provided to support the procedure used and the result achieved?
Current methods make it virtually impossible to realise target concentration and require mathematical corrections to be made. With the high cost of novel compounds and standard control materials, buying and maintaining glassware, the environmental impact, costs and disposal of solvents and lack of traceability of the standards, has become a serious concern and also questions the analytical integrity of al data.
Technology does not always provide the answer. However it can offer novel approaches where current procedure may be considered questionable or outmoded.
ESSLAB has integrated two leading manufacturers of high-precision weighing and liquid handling instrumentation into a fully compliant software-controlled app that will prove to assure confidence and traceability of reference materials used as part of a laboratory's quality control of research programmes.
It allows the systematic control for the preparation of standards offering:
• Company /Department Identification.
• Analyst Identification through 21 CFR compliant control
• Compound (solute) identification
• Compound Purity concentration correction
• Compound Batch/Lot Identification
• Selectable concentration unit selectable (µg/ml/ppm/mmoles/ltr.)
• Solvent Identification
• Solvent Density correction
• Selectable Concentration
• Selectable Volume
• Target solute weight confirmation
• Actual weight/volume confirmation
• Volume validated through density correction
The MicroLab-GDS app integrates balance and dispenser through the balance interface. The app guides the user step-by-step through the specific workflow. It is therefore guaranteed that the procedures described in the corresponding SOPs are observed at all times.
It is a means by which precise and accurate solutions may be prepared, error-free, first time, every time, without volumetric glassware, to an accuracy that would be difficult to match with standard techniques, and with complete traceability.
As the preparation is not reliant on the technique of the analyst, it is clearly a major advance in laboratory procedure. For accredited laboratories there is a necessity to include check weigh procedures between full calibration, on a daily basis or before use. The system incorporates a verification function that identifies full traceability of the values through use of OIML weights with their expression on uncertainty giving confidence that correct value has been realised.
The principles through which the MicroLab-GDS system operates provide the most significant step in achieving a laboratories proficiency goal and reducing cost
It offers:
• Standards preparation without volumetric glassware
• Traceable & documented standards preparation compliant with GLP
• Verification of precision and accuracy through OIML weights
• No secondary validation
• Correction for purity of solute and density of solvent
• True concentration realised, no mathematical corrections
• Lot traceability of solutes & solvents
• Error-free standards preparation – first time every time
• Precision and accuracy independent of analyst
Errors made through the use of unreliable data, quantifying the presence or absence of measurements accurately and reliably, is major concern but may be avoided.
