Easy moisture determination in fertilizers by near-infrared spectroscopy

Blooms or bombs?

As the global population steadily increases, it is important that sufficient crops are produced each year to provide enough food, clothing, and other products. Crops such as corn, wheat, soy, and cotton receive nutrients from the soil they are grown in. Fertilizers play a crucial role in providing these crops with the nutrients they need to grow properly.

Moisture analysis methods for fertilizers

During the production process of ammonium nitrate it is important to control the moisture content. A low moisture content is preferable, but unnecessary excess drying leads to additional manufacturing costs.  Regulations for different fertilizers vary across the globe, but local legal limits ensure that the maximum amount of water present must not be exceeded.  Therefore,  rapid, reliable, and accurate methods for the determination of moisture is necessary. Out of those available, Karl Fischer titration is one of the most common; oven drying, for example, cannot be used with fertilizers containing ammonium nitrate.

Compared to these methods, near-infrared spectroscopy (NIRS) offers unique advantages. It is a secondary technique that generates reliable results within seconds without needing any sample preparation. NIRS is a non-destructive measurement technique and at the same time does not create any chemical waste.

Read our previous blog posts below to learn more about NIRS as a secondary technique.

Benefits of NIRS: Part 1

Benefits of NIRS: Part 2

Benefits of NIRS: Part 3

Benefits of NIRS: Part 4

As the DS2500 Solid Analyzer is a pre-dispersive system, the sample is illuminated with monochromatic light in order to keep the energy level as low as possible. Therefore, the instrument lid must be closed prior to starting the analysis so external light does not affect the results.

Advantages of using NIRS

The procedure for obtaining the NIR spectrum already highlights its simplicity regarding sample measurement and its speed. Several advantages of NIRS are listed below:

• Fast technique with results in less than 1 minute.
• No sample preparation required – solids and liquids can be used in pure form.
• Low cost per sample – no chemicals or solvents needed.
• Environmentally friendly technique – no waste generated.
• Non-destructive – precious samples can be reused after analysis.
• Multiple component analysis – prediction of different constituents in parallel.
• Easy to operate – inexperienced users are immediately successful.

Overall, near-infrared spectroscopy is a robust alternative technique for the determination of both chemical and physical parameters in solids and liquids. It is a fast method which can also be successfully implemented for routine analysis by staff without any higher laboratory education.

Related Applications

Specialty chemicals have to fulfill multiple quality requirements. One of these quality parameters, which can be found in almost all certificates of analysis and specifications, is the moisture content. The standard method for the determination of moisture content is Karl Fischer titration.

This method requires reproducible sample preparation, chemicals, and waste disposal. Alternatively, near-infrared spectroscopy can be used for the determination of moisture content. With this technique, samples can be analyzed without any preparation and without using any chemicals.
 

More information about the application details can be found here:

Quality control of Ammonium Nitrate – Rapid and non-destructive moisture determination

Moisture content is one of the most commonly measured properties of fertilizers. Globally, regulations for different fertilizers vary, but local legal limits ensure that the maximum amount of water must not be exceeded. A number of analytical techniques are available for this purpose. Next to gravimetric methods, Karl Fischer titration is often used for accurate moisture determination.

Compared to these methods, near-infrared spectroscopy offers unique advantages: it generates reliable results within seconds, and at the same time does not create chemical waste. The Application Note below explains how NIRS can offer fast, reagent-free analysis of moisture content in various fertilizer products.

Moisture analysis in fertilizer products – Results in seconds with NIR Spectroscopy

Your knowledge take-aways

Moisture Analysis – Karl Fischer Titration, NIRS, or both?