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6th Research/Expert Conference with International Participations
”QUALITY 2009“, Neum, B&H, June 04 – 07, 2009
QUALITY ASSURANCE AND QUALITY CONTROL IN CHEMICAL
AND PHYSICAL ANALYSIS
Klodian Dhoska, inxh.i dipl.
Faculty of Mechanical Engineering
Dr.sc. Jorgaq Kacani
Faculty of Mechanical Engineering
MSc. Altin Dorri
Faculty of Mechanical Engineering
Mr.Sc. Vehbi Ramaj
Analytical measurements are important part for many human activities and in such cases they used in
order to take important decision in the problem of economy, technology of production, environment,
legislation etc. Evaluation of quality in different productivities and materials, process control of
produce, consumer assurance, environment protection and healthy safeguard of people are some of
the important activity that based in chemical and physical analysis. Basic problem for all quality
system is establishment of reliability in the results that give laboratory. But, reliability toward the
laboratory must exist only if it based in reliability of measurement which prove these quality. Today
the important problems of analytical measurement are establishment of quality system, quality
assurance and quality control of measurements in analytical laboratory. In the end of this purpose is
that laboratory must provide to consumers some analytical data with known quality (acceptable).
Keywords: assurance, control, analysis, quality, laboratory.
Analytical measurements are important part for many human activities and in such cases they
used in order to take important decision in the problem of economy, technology of
production, environment, legislation etc. Evaluation of quality in different productivities and
materials, process control of produce, consumer assurance, environment protection and
healthy safeguard of people are some of the important activity that based in chemical
analyses. One important point of this reason is the including always in growing the number of
the countries in International Economic and Trade. Essential request is the assessment of
produce and service that will be compared between different countries. Today, for this
purpose precede some national and international organization which have for their object
work the standardization of a measurement method, quality of product and accreditation of
laboratory. For aftermath can remember directive and international and European standards
which help a lot in quality assurance and quality control. Important standard which used in
these fields are ISO/IEC 17025 “General requirements for the competence of testing and
calibration laboratories” and ISO/IEC 9000 “Quality Management System”. Basic problem
for all quality system is establishment of reliability in the results that give laboratory. But,
reliability toward the laboratory must exist only if it based in reliability of measurement
which prove these quality. Today the important problems of analytical measurement are
establishment of quality system, quality assurance and quality control of measurements in
analytical laboratory. In the end of this purpose is that laboratory must provide to consumers
some analytical data with known quality (acceptable) [1,2].
2. QUALITY SYSTEM IN ANALYTICAL LABORATORY
One of the basic problems in nowadays is reliability of the analytical result almost in the field
of international trade, environmental protection, and transport accuracy, implementation of
the legislation and normative, medical treatment and healthy safeguard of people. For a long
time was looked which will be necessity to assesses the performance of the method and to
monitored the quality of analysis. Method that is used for this reason has been from different
way starting by assessment of the experience capacitive of analyst until rigorous assessment
of the statistical method. The result of the analysis may be consider as the product of the
analytical laboratory and says that their quality can assess and improve. Quality system of the
laboratory shall include all the aspect of their work and will be able to demonstrate that their
service is with best quality. These does it means that could take in consideration all the
components of quality system which are shown in the figure 1.
In order to evaluate the performance of the method in chemical and physical analysis and a
quality of the obtained results is needed to establish which parameters shall be determined in
method. Most of the cases required to evaluate the precision, accuracy of the method,
systematic error (bias), selectivity and specificity. One important characteristic in chemical and
physical analysis is own connection in directly manner with object that analyze as is the sample.
Furthermore, establishment of quality system made the possibility to prevent errors in
accomplishment of analysis and the effects that are in connection with it. The prevention of the
errors decreases necessity to repeat the analysis and the importance is to avoid the possibility
that errors of the result to arrive at clients. The reason in quality system is to guarantee if are
describe all detailed needed, in the manner that all the links of quality measurement are in
control and after will see that all the analytical results are with quality declared[2,3].
Figure 1. Construction scheme for quality system
2.1 Factor that influence in organization and operation of the quality system
The important factor that influence in organization and operation of the quality system at
analytical laboratory are:
• Economical factor
• Infrastructure (tools, environmental and apparatus)
• Level staff and their motivation
Meanwhile, tools that have available analytical laboratories for constructing the quality
• Apparatus (level and their maintenance), reagents and other materials
• Reference materials (RM) and certificate reference materials (CRM)
• Evaluation method and quality control charts
• Inter-laboratory Comparison
• Qualification and training staff
• Quality manual
All the staff of laboratory shall include in quality system to beginning from general manager,
analyst and assistant personal. Best manner to ensure that quality system work in good
condition is that it allocates one person or one commission, independent from laboratory staff
which has responsibility to control and improve the quality system [3,4].
Figure 2: Organization scheme for analytical laboratory
In order to improve the effectiveness of the quality assurance system is needed to use
frequently audits which may proceed from external specialist but shall proceed and internal
periodical control to evaluate the effectiveness of the special analyst or special part of the
The difficulties in establishment of quality system in chemical and physical laboratory must
be different but we remember:
1. Management not sufficient
2. Time and sources that are needed in order to establish the quality system and to
maintain with effectiveness by means of quality control.
3. Undervalue of the training for qualification and specialization.
4. Insufficiency of financial sources, quality of the devices and reagents are not in good
5. Deficiency of the reference materials and not good environmental condition of the
3. QUALITY CONTROL IN CHEMICAL AND PHYSICAL LABORATORY
Quality control in analytical laboratory realized by means of some manners:
a. Quality control from statistical manner.
b. Internal control of quality in analytical laboratory
c. External control of quality by means of inter-laboratory comparisons.
a. Statistical methods are used in order to improve the quality of the production and processes
which includes the quality of chemical and physical analysis. Some of these instruments are
shown in schematically manner below in example figures.
Figure 3: Diagram cause-effect Figure 4: Flow chart
Figure 5: Histogram Figure 6: Diagram Pareto
Figure 7: Correlation chart Figure 8: Control chart
b. An internal control of quality in analytical laboratory is composed by some components
which are rank as below:
• Certification the competence of analyst – Before load the analyst to achieve analysis
is better to prove the competence of analyst. Every time is needed from analyst to
demonstrate the acceptance precision and no systematic errors during the analysis.
• Reclamation of the Supplement Standard Method – This is used when we want to
analyze new matrices, to prove the interference of matrices. Supplement Standard of
analytic should be 5 until 50 times higher than limit of detection but will be internal
of the linear area from calibration curve.
• Analysis of the standard sample which is prepared outside the laboratory – In this
case we have RM or CRM that are prepared outside the laboratory.
• Analysis of the white exhibit – It is needed that 5% of analyzed sample should be
from white exhibit because is very important to control the purity of reagents and the
other possible impurity in all work procedure.
• Evaluation of calibration – Standard calibration shall do every time that we want to
do the analysis. Minimal number of standard calibration is 3. Recommended to
verify every time the calibration curve for changes or not.
• Analysis of parallel exhibit – We can assess the determination precision from
analysis of parallel exhibit.
c. External quality control in analytical laboratory has the general objective where the given
results by different laboratory shall be comparing. This will realize by comparison laboratory.
The laboratory attends comparison laboratory which analyze one or some identical homogeny
sample in specify condition and assessment of the obtain results are shown in one unique
In the end of this study will say that if we know how to assurance and control the quality in
analytical measurement we arrived in conclusion which is very important to solve the
problems and to stop the technical barriers in different field for these reasons:
• Technological, economical, legislative, technology of the produce and environmental
• Assurance that we give to consumer, healthy safeguard of the people and
• Growth of the product and service quality is one occurrence characteristic for
nowadays which grow the role of analytical measurement in the life of the country.
• Including always in growing the number of the countries in International Economic
and Trade which have basic requirement to realize the evaluation of the product and
service in comparison between different countries.
• Different laboratory assurance to consumer analytical data with acceptance quality.
 EUROCHEM Guide - Guide to quality in analytical chemistry – an aid to accreditation, 2002
 AOAC International - Quality Assurance Principles for Analytical Laboratories - 3rd Edition
2000 - F M Garfield, E Klesten, J Husch ISBN-0-935584-70-6
 P. De Bievre and H. Gunzler - Traceability in Physical and Chemical Measurement
 Prof. Dr. Alqi Cullaj - Sigurimi i cilesise dhe kontrolli i cilesise ne analizat kimike, 2002
 EUROCHEM Guide – Quality assurance for research and development and non routine
 V. I. Dvorkin – Interlaboratory Quality Control of Chemical Analysis with Reference Materials
at Disposal, 2000