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Sampling Methods: Sample Types

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Sampling materials are classified into three main types: solid, liquid, and gas.
Solid samples include a variety of substances, such as sediments from water bodies, soil, metals, and biological tissues. Two standard methods for extracting sediments from water bodies are grab sampling and piston coring. Grab sampling involves using a device to collect a discrete sediment sample from the bottom of a water body with minimal disturbance. Grab samples do not always represent the entire area due to...

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Updated: Apr 15, 2026

Sampling Soils in a Heterogeneous Research Plot

Sampling Soils in a Heterogeneous Research Plot

Published on: January 7, 2019

Materials properties: heterogeneity and appropriate sampling modes.

Journal of AOAC International

|March 26, 2015

Summary

Understanding material heterogeneity is crucial for accurate sampling in food and feed sectors. This paper explains sampling errors and how the Theory of Sampling mitigates them.

Area of Science:

Food Science
Analytical Chemistry
Sampling Theory

Background:

Effective decision-making relies on accurate analytical results, which are preceded by primary sampling.
Heterogeneous materials present significant challenges in sampling, potentially leading to errors.
The Theory of Sampling provides a framework for managing these challenges.

Purpose of the Study:

To elucidate the phenomenon and concepts of material heterogeneity in sampling.
To describe the adverse effects of heterogeneity on sampling processes.
To provide strategies for understanding, describing, and managing sampling errors caused by heterogeneity.

Main Methods:

Discussion of sampling errors arising from material heterogeneity.
Explanation of the principles of the Theory of Sampling.

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Last Updated: Apr 15, 2026

Sampling Soils in a Heterogeneous Research Plot

Sampling Soils in a Heterogeneous Research Plot

Published on: January 7, 2019

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Published on: March 13, 2014

Methods of Soil Resampling to Monitor Changes in the Chemical Concentrations of Forest Soils

Methods of Soil Resampling to Monitor Changes in the Chemical Concentrations of Forest Soils

Published on: November 25, 2016

Conceptual analysis of managing heterogeneity in sampling processes.

Main Results:

Identification of up to five types of sampling errors related to heterogeneous materials.
Distinction between errors originating from the sampling target's heterogeneity and those from the sampling process itself.
Emphasis on the necessity of understanding and managing heterogeneity to ensure reliable analytical outcomes.

Conclusions:

Competent understanding of heterogeneous material characteristics is essential for all stakeholders in the food and feed sectors.
Proper sampling, guided by the Theory of Sampling, is critical to counteract heterogeneity effects.
Effective management of sampling errors is key to delivering dependable analytical results for decision-making.