MAIN LABORATORY
The Quality Control Department is a key organisational unit of the Main Laboratory for Water at the Josip Juraj Strossmayer Water Institute (MWL). Its primary task is to ensure the implementation, improvement, and maintenance of the quality management system in accordance with the HRN EN ISO/IEC 17025:2017 standard. This standard sets out the general requirements for the competence of testing and calibration laboratories.
The implementation of a quality management system aims to enhance the quality of laboratory operations, monitor the suitability of applied methods and develop new ones, identify trends and deviations through continuous assessment of analytical data quality, and monitor the validity of equipment, chemicals, and tools, as well as environmental conditions, staff competencies, procurement of equipment and supplies, and other laboratory processes. Clients of the MWL can rely on the accuracy of the test results, knowing that all laboratory work is conducted in compliance with prescribed rules and requirements. High-quality and reliable test results regarding the chemical and ecological status of water bodies are essential because they form the basis for making critical decisions, such as water management plans.
The conformity assessment of the quality management system with the requirements of the HRN EN ISO/IEC 17025:2017 standard is conducted by the national accreditation body, the Croatian Accreditation Agency (HAA).
MWL is the successor of the Main Water Management Laboratory of Hrvatske vode, which was first accredited by HAA in 2013 following a document review and an evaluation of the system and analytical methods. Since then, the scope of accreditation has been continuously improved and expanded to include new methods for testing chemical and biological indicators in surface water, groundwater, and wastewater sampling and analysis, as well as river sediment examination.
Quality control activities encompass the development and enhancement of quality system documentation, the planning and evaluation of participation in interlaboratory comparison tests, and the monitoring and updating of legal and technical regulations and methodologies. They also include providing support and collaboration with lead analysts in drafting validation protocols, reports, and control charts, conducting internal independent assessments of methods and systems, compiling the annual quality system report, and preparing documentation for external accreditation assessments and any subsequent expansions of the accreditation scope.
The quality system documentation defines the organisation, equipment, facilities, and staff responsibilities and includes regulations and guidelines for performing procedures, applying methods, and overseeing various aspects of laboratory work.
It comprises the Quality Manual, management system procedures, standard operating procedures, work instructions, forms, and various records.
The Quality Manual (QM) is the fundamental document of the quality system, outlining the quality policy, documentation structure, organisational framework, and procedures related to equipment management, procurement, documentation control, and authorisations, as well as procedures affecting test results, with references to all procedures, work instructions, and forms.
The Management System Procedures (MSP) further define general activities and processes that may impact testing quality. For instance, the PSU document on document drafting and revision defines the format, labelling, and distribution of documents, while the PSU procurement procedure outlines the process for acquiring chemicals, standards, equipment, and supplies that may impact test results. It also specifies how the quality of procured items is to be assessed and how suppliers are to be evaluated.
The Work Instructions (WI) provide detailed procedural guidelines, elaborating on activities mentioned in the QM or MSP, such as creating control charts, preparing validation protocols for testing methods, registering samples in LIMS, cleaning laboratory glassware, calibrating and maintaining equipment etc.
For all testing methods used in the laboratory, a Standard Operating Procedure (SOP), a validation protocol, and a validation report are prepared. Validation involves conducting various tests to confirm that a method meets the analytical requirements the laboratory must adhere to.
Laboratories utilise different testing methods: standardised testing methods (HRN, ISO, EPA, Standard Methods), application-specific methods (developed or recommended by equipment manufacturers), and in-house methods developed within the laboratory
Quality control measures for applying and monitoring analytical testing methods can be classified as external and internal.
External quality control measures include participation in interlaboratory comparisons (ILC) and independent external assessments (HAA)
Interlaboratory comparison tests are conducted by analysing samples with unknown concentrations across all available parameters tested by the laboratory. ILC provides objective evidence of a laboratory’s competence in terms of performing specific tests and represents a mandatory component of the quality assurance system related to test results.
The regular use of certified reference materials (CRM) for calibrations and control chart preparation, the use of blank samples, internal independent audits (IIA), periodic competency assessments, and others are just some of our internal quality control measures. For instance, internal audits (IIA) of certain methods are conducted annually following a five-year quality control plan. During an IIA process, records are reviewed to confirm that methods and procedures are applied as prescribed, and that equipment and chemicals comply with regulations. Any detected deviations (non-conformities) must be corrected. Additionally, internal audit of the quality management system is also carried out annually, followed by the preparation of a quality system status report. The management is informed of all activities undertaken, and as part of the “management evaluations”, decisions are made regarding the further development of the laboratory, equipment acquisition, new analytical methods that need to be developed, system improvements, and so on.