Documented technical analytical instructions
An efficient and sustainable organization of the technical work carried out in the XRF Laboratory requires of the definition and establishment of documented technical analytical instructions. Such procedures allow ensuring the harmonization in XRF work practice and fulfilment of minimal requirements for ensuring a commensurable quality of the analytical results. The technical analytical instructions shall include:
- A clear definition of the scope of the procedure. The definition of the scope shall explicitly contain: type of material, analytes to be determined and applicability concentration range, method to be used.
- A technical description of the theoretical (or implicit) principles on which the instruction is based on. At least a basic description of the analytical procedure shall be explained. References can be made to published papers, standards or technical texts for in-depth knowledge.
- The main steps to be followed and the sequence of tasks to be performed. This section is the main content in the procedure, since it is meant to ensure that the procedure can be repeated by technical staff. Therefore, each step shall be unequivocally described. Local slang or non-conventional terms shall be avoided.
- The format to report the achieved results. The procedure shall specify the units to express the results and a clear statement of the calculated uncertainty. Avoid reporting non-significant digits!
- A clear statement of the criteria of quality performance achieved. Main figures of performance are: detection limits, precision and trueness of the results. A detailed explanation on calculated uncertainty must be provided.
for example, a procedure can be prepared for: