CCIL Sample Management and Preparation 5

Question 1

Which ISO/IEC standard governs the general competence requirements for testing and calibration laboratories, including sample management practices?

Accepted Answer

ISO/IEC 17025

Answer

ISO/IEC 17025 is the international standard specific to testing and calibration laboratory competence, encompassing sample receipt, handling, and traceability.

Question 2

When a laboratory must store samples at -20°C for organic analysis, which container closure is MOST appropriate to prevent cross-contamination?

Accepted Answer

Teflon-lined screw cap sealed with parafilm

Answer

Teflon-lined screw caps with parafilm provide an inert, solvent-resistant seal that prevents both contamination and evaporation loss during frozen storage.

Question 3

A sample for dissolved metals analysis must be filtered through what pore size before acidification?

Accepted Answer

0.45 µm membrane filter

Answer

The 0.45 µm pore size is the internationally accepted cutoff that operationally defines 'dissolved' versus particulate-bound metals.

Question 4

In a LIMS (Laboratory Information Management System), which feature MOST directly supports sample integrity?

Accepted Answer

Barcode or RFID tracking linking each sample aliquot to its chain-of-custody record

Answer

Barcode or RFID tracking creates an automated, tamper-evident link between physical samples and their electronic records, reducing transcription errors.

Question 5

What action must be taken when a sample holding time is exceeded BEFORE analysis?

Accepted Answer

Analyze the sample and flag results as potentially compromised in the report

Answer

Exceeded holding times must be documented and reported to the client, as results may not be defensible but the client must make the final decision.

CCIL - Canadian Council of Independent Laboratories Practice Test

CCIL - Canadian Council of Independent Laboratories Practice Test

CCIL Sample Management and Preparation 5