Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 1/9)
Character Range: 716337–719523

3                   Quality assurance and quality control

3.1              Definitions
The terms 'quality assurance' and 'quality control' are often misinterpreted. This guideline defines them as follows (ISO 8402–1994):

'Quality assurance (QA) is all the planned and systematic activities implemented within the quality system and demonstrated as needed to provide adequate confidence that an entity will fulfil requirements for quality.'

This encompasses all actions, procedures, checks and decisions undertaken to ensure the accuracy and reliability of analysis results. It includes the application of routine documented procedures to ensure proper sample control, data transfer, instrument calibration, the decisions required to select and properly train all staff, select and maintain equipment, select analytical methods, and the regular scrutiny of all laboratory systems and corrective actions applied forthwith.

Quality control (QC) is 'the operational techniques and activities that are used to fulfil the requirements for quality'.

These are the QA components that serve to monitor and measure the effectiveness of other QA procedures by comparing them with previously decided objectives. They include measurement of reagent quality, apparatus cleanliness, accuracy and precision of methods and instrumentation, and reliability of all of these factors as implemented in a given laboratory from day to day.

A complete discussion of either of these terms or the steps for implementing them is beyond the scope of this guideline; suffice to say, sound laboratory QA systems and QC procedures are essential. In brief, laboratories should incorporate quality laboratory management systems and participate in accreditation and/or self-audit systems, to ensure reliable results are produced by trained analysts, using validated methods and suitably calibrated equipment, and to maintain proper sample management and recordkeeping systems.

For more information on good laboratory practice and QA procedures, refer to guidance from NATA (Cook 2002) and Standards Australia (AS 2830.11985).

3.2              Method validation
This is the process of obtaining data on a method in order to determine its characteristic performance and to establish confidence in the use of that method to provide reliable results. Method validation needs to be performed by each laboratory before that method is adopted and applied to the analysis of actual samples.

It is difficult to obtain complete validation data for all analytes covered in these guidelines due to large variations in soil types and physicochemical properties, and lack of suitable or reliable reference standard materials. For some analytes (e.g. soil pH), conventional validation data has no bearing on method performance between one soil sample and the next; for such analyses, better performance indicators may be obtained through inter-laboratory comparisons.

This guideline recommends certain extraction procedures or, in some cases, complete methods—each laboratory should fully validate each method used (from extraction through to the determinative step) following the principles for quality assurance and method