Moisture Content Analysis

Loss on Drying (LOD) refers to the determination of the moisture or volatile content in a material by measuring the weight loss after subjecting the material to controlled heating and drying conditions. The method is commonly used across various industries, including pharmaceuticals, food, chemicals, and materials testing, to quantify the moisture content or volatile components in a sample. The purpose of determining the loss on drying is to assess the amount of moisture or volatile substances present in a material. It’s crucial for quality control, manufacturing processes, and ensuring compliance with specific industry standards or regulations.


A representative sample of the material to be tested is obtained and an empty weighing boat is weighed accurately by a balance. The weigh of the initial mass of the sample (before drying) is taken together with the weight of the weighing boat using a balance.

The sample is placed in an oven set at a specified temperature and maintained at this temperature until the sample reaches a constant weight. The temperature and drying time may vary based on the material being tested and the requirements outlined in the specific test method. The drying is typically conducted under vacuum. After drying, the sample is allowed to cool in a desiccator before reweighing it.  The weight of the dried sample is then taken to determine the final moisture content.

Applicable Standard

ASTM E1131-08 is the standard test method for the determination of the loss on drying (LOD) of solid materials. This method is used to measure the moisture content of materials by determining the weight loss upon drying.

When to perform Moisture Content Analysis

This method is commonly used for various materials to determine the moisture content or volatile content by measuring the weight loss due to evaporation of moisture or other volatile components during the drying process. However, specific industries and materials might have their own ASTM standards or variations tailored to their characteristics, so it’s essential to refer to the appropriate ASTM method relevant to the material being tested.

Why work with Prime Process Safety Center

  • Prime Process Safety Center is a leader in process safety testing with very experienced laboratory personnel. At Prime Process Safety Center our goal is to provide accurate, reliable and defensible data that meets industry and regulatory standards. We understand the need for the quality of your data, and we work assiduously to achieve just that.
  • We are knowledgeable and experienced in performing moisture content analysis tests, ensuring accurate and reliable results.
  • We have state-of-the-art moisture content analysis testing equipment, providing precise and sensitive measurements.
  • We follow strict testing protocols and quality control measures to ensure consistent and reliable test results.
  • Our team can interpret and analyze the data obtained from the tests, providing valuable insights and recommendations for your specific application or research.


Why is Loss on Drying (LOD) analysis important?

Answer: LOD analysis is crucial as it determines the moisture or volatile content in a substance. This data is vital for quality control, ensuring product stability, meeting industry standards, and preserving product integrity. For pharmaceuticals, food, chemicals, and various manufacturing processes, maintaining specific moisture levels is essential.

What's the basic principle behind LOD analysis?

Answer: LOD analysis measures the weight loss resulting from the removal of moisture or volatile substances when a sample is subjected to controlled heating or drying conditions. By comparing the initial and final weights of the sample, the percentage of moisture content or volatile substances can be calculated.

What factors can influence LOD analysis results?

Answer: Several factors impact LOD results, such as the drying temperature, duration, sample homogeneity, container type, handling procedures, and the presence of other volatile components in the material being analyzed. Inaccuracies can arise from improper drying conditions or inadequate sample preparation.

How does LOD analysis differ from moisture determination by Karl Fischer titration?

Answer: LOD analysis involves drying a sample to remove moisture or volatiles and then measuring the weight loss. Karl Fischer titration is a technique specifically designed to quantify water content through a chemical reaction. LOD measures overall weight loss, whereas Karl Fischer titration measures water specifically.

What are the common methods used for LOD analysis?

Answer: The most common methods for LOD analysis involve heating a sample in an oven under controlled conditions (as per ASTM E1131) or using specialized instruments like moisture analyzers or desiccator methods. Each method has its specific procedures tailored to different industries and materials.