Download presentation
Published byAbigail McDonough Modified over 10 years ago
1
An Introduction to Quality Assurance in Analytical Science
Dr Irene Mueller-Harvey Mr Richard Baker Mr Brian Woodget
2
Part 3 - Quality systems Contents:
Introduction to quality systems (slides 3,4) QA and QC systems (slides 5-9) Measurement traceability (slides 10,11) Reference materials and check samples (slide 12) Keeping track of samples (slide 13) Quality manual (slides 14-17) Quality system filing (slide 18) The presentation contains some animation which will be activated automatically (no more than a 2 second delay), by mouse click or by use of the ‘page down’ key on your keyboard.
3
Without a Laboratory Quality System -
too many mistakes can make analysis very costly; due to costs of analysis expenses caused by wrong decisions, or repeating analysis of samples investigation of problems revision of procedures loss of good reputation
4
Prevention is Better than cure!
‘It costs less to prevent a problem than it does to correct it’ A formal quality system in the laboratory should prevent mistakes by means of: quality assurance measures quality control of the analytical results thorough documentation of the system efficient maintenance of records regular audits of all aspects of the system
5
QA and QC systems Quality Control: Quality Assurance:
planned activities designed to provide a quality product. Quality Assurance: planned activities designed to ensure that the quality control activities are being properly implemented. (As defined by the Association of Official Analytical Chemists)
6
QA Systems Quality Assurance measures apply to the laboratory analytical work overall, which includes; identifying the person having the overall responsibility for quality having laboratory equipment calibrated to recognised standards using reference materials joining proficiency testing schemes with other laboratories doing similar tests
7
QC systems reagent blanks; verified standard solutions; blind samples
Quality control measures apply to each analytical test in the laboratory by use of: Control chart reagent blanks; verified standard solutions; check samples (from both within the lab and from outside); blind samples replicate analyses; and control charts
8
Quality systems - control charts
A control chart is a means of ensuring that the method remains in ‘control’ - continues to perform in accordance with expectations. This usually means that results from analysing standards fall within + 2 standard deviations of the accepted value (within the blue lines on the chart). Any results appearing outside the red lines (+ 3 standard deviations) indicate that the method is not longer in control and requires investigation.
9
Use of QC Samples Step change Regular analysis of a single control sample will identify a system in or out of control conditions Bias Target value Drift In control Daily QC data
10
Measurement traceability
In an absolute sense, the ‘true’ value can be defined only as being that value directly traceable to the base system of measurement (SI) or their derivatives - ie: to national or international standards via an unbroken chain of comparisons SI unit Transfers accuracy Provides traceability Certified reference material Laboratory working standard Analytical method
11
Measurement traceability (2)
The Sample Analysed by The SI units: Kg, Metre, Mole Secondary method: e.g. lab. method Calibrated by Primary methods (often gravimetric) e.g. AOAC, EPA Calibration Standards Method routinely checked by Certified by analysis Primary methods are often based on gravimetric procedures (e.g. AOAC, EPA methods) Secondary RMs In-house QC materials (fairly cheap, larger amounts, matrix matched, short life) Certified Reference Materials (CRMs - expensive, small amounts, best accuracy, long life) Periodically checked 1
12
Reference materials & check samples
SUPPLIED FOR PROFICIENCY TESTING INTERNAL QC SAMPLES Internal QC samples are prepared and quantity values of target components are checked against CRMs An accredited laboratory has to prove its performance by routinely analysing samples supplied by an independent laboratory CERTIFIED REFERENCE MATERIALS (CRMs)
13
Keeping track of the samples
Lab. No. F7-002 Sample registration gives each sample a unique lab number. The sample register records all the information about the sample. Just like a sample’s passport, you should not confuse any sample with any other. The history of the sample should be traceable throughout. Sample integrity Samples recorded on receipt 1
14
Quality Manual A quality manual defines the quality system under
Laboratory Quality System Quality Manual Admin Page 1 of 1 Amiable Laboratory Issue No. Issue Date Title of Section Title Page Issued by QUALITY MANUAL for Amiable Laboratory Benevolent Department Well-intentioned Organisation Usual Location A quality manual defines the quality system under which the laboratory operates This Manual is issued under the authority of Issue Date Issue No. 3 Copy No. A Person Holder Head of Laboratory Quality Manual - cover page
15
Quality Manual - contents (1)
16
Quality Manual - contents (2) -
17
Quality Manual - contents (3)
18
Quality system files 1. Admin Audit reports System reviews Blank forms
Memos Notices Quality Manual Record of anomalies Preventive actions 1.2.1.(index) General contract 2. Validation Fibre Milk Proficiency test 3. Equipment 3.01 Equip records 3.02 Operating procedures balance ovens muffles thermometers pH meters List of General Procedures 4. Procedures Quality control records Reference standards Result acceptability Result reporting Result uncertainties Sample disposal Sample reception Sample registration Staff records System reviews Training and competence Recording and storing data Document control Calibration records Complaints and anomalies Equipment records Method validation Quality audits 5. Quality Control Fibre analysis Milk analysis Feed analysis N by combustion Q.C. limits Test reports & log 6. Staff Records Job descriptions 7. Standard Methods ADF Dry matters Fat, protein & lactose in milk NDF 1
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.