##  [Sample Custody Log](/sample-custody-log-0) 

 Definition

A sampling and analytical workflow concept defining how ocean materials are collected, documented, and measured for study. It governs equipment selection, handling procedures, and quality checks that preserve sample integrity and measurement reliability. It does not ensure data quality without contamination control, traceable metadata, and repeatable analytical methods. It materially affects interpretability by ensuring that observations are reproducible and correctly linked to place and time. The concept is generally stable, though tools and automation for sampling and logging improve over time.



 

 

 

 

 

 





## Principle

Principle

Ensure transparency, accountability and reproducibility of sample-based results by recording who handled each sample, when, under what conditions and for what purpose, so provenance and potential contamination or alteration are assessable.

 

 

 

 

 





## Demonstration

Demonstration

A sample custody log entry for a sediment core interval includes sample ID, source core and depth interval, date/time of removal, name and signature of the person taking the sample, storage container type, preservation method (e.g., frozen, refrigerated, ethanol), transfer events (onboard to shore lab), and final repository location.

 

 

 

 

## Misapplication

Misapplication

Maintaining incomplete, inconsistent or retrospective custody notes that omit transfer events, storage-temperature deviations or handler identification, undermining the ability to interpret sample integrity or to defend results during review.

 

 

 

 

 





## Consequence

Consequence

A complete custody log supports data quality assessments, permits reconstruction of handling histories when anomalies arise, facilitates compliance with legal or regulatory requirements, and enables reliable re-use of samples.

 

 

 

 

## Reversal

Reversal

No custody documentation: samples handled without recorded provenance or transfer history, leaving provenance unverifiable and increasing risk of misattribution or compromised data.

 

 

 

 

 





## Boundary

Boundary

Covers physical sample objects and their direct containers and transfers; does not replace instrument data logs, metadata records for derived datasets, or informal notes that lack authenticated timestamps and handler identification.

 

 

 

 

 





## Semantic Tension

Semantic Tension

Tension exists between the administrative overhead of exhaustive custody recording and operational constraints in the field or shipboard environment; pragmatically designed logs balance completeness with practicability.

 

 

 

 

 





## Synthesis

Synthesis

The Sample Custody Log is the formal, time-stamped record of every custody and handling event for physical samples that documents provenance, storage and transfers to ensure traceability, support quality judgments, and protect the integrity of sample-derived results.