Osmometers are designed to measure the osmolality of a solution. They measure changes in a solution’s colligative properties, such as freezing and boiling point, vapor pressure and osmotic pressure, which are proportional to the concentration of solute present. As particles are introduced into a solvent, freezing point and vapor pressure are lowered, but boiling point and osmotic pressure are elevated.

The two most common ways of determining the osmotic strength of a sample are by measuring the freezing-point depression or changes in vapor pressure. Although both freezing-point and vapor-pressure osmometers provide scientists with fast and inexpensive measurements, freezing-point osmometers generally give more accurate measurements. However, a disadvantage of freezing-point osmometers is that they are limited to low-viscosity solutions. In contrast, vapor-pressure osmometers are generally used with more viscous solutions, but their use is limited to homogeneous mixtures.

Osmometers are commonly used in clinical and diagnostic applications. For example, osmometers are often used to determine mineral concentrations, such as salt, in urine and blood. They can also be used to evaluate renal function and diabetes and to determine and monitor drug and alcohol intoxication states.

Osmometers are also used in the pharmaceutical industry at various stages of drug development, including drug discovery, formulation and manufacturing. Osmometers’ biotechnology applications include determining the proper concentration of dissolved solutes in solvents used in cell analysis, molecular biology and other applications.

Advanced Instruments is the leading provider of freezing-point osmometers. The company manufactures an array of freezing-point osmometers designed for both single and multi-sample analysis. The company also offers aftermarket products for its systems, such as components, autosamplers, reagents and standards.

Precision Systems also manufactures freezing-point osmometers. The company’s 5010 OSMETTE III accepts 10 µl samples and has a range of 0–2000 mOsm/kg, while its 5007 OSMETTE XL is a fully automated system that can accept samples of up to 2 mL and has a range of 0–3000 mOsm/kg.

Wescor is a top vendor of vapor-pressure osmometers. Its Vapro 5600 system is an advanced osmometer with self-cleaning capabilities. The system can accept samples of 10 µl, which can be extended to either 2 µl or 60 µl with the appropriate sample handler.

Even though the overall market growth for osmometers is modest, applications in the pharmaceutical and biotechnology industries are expected to drive the market. The use of osmometers in sports medicine has also become widespread and is among the fastest- growing areas of the market.

Osmometers at a Glance:

Leading Suppliers

• Advanced Instruments

• Wescor

• Precision Systems

Largest Markets

• Clinical

• Pharmaceutical

• Biotechnology

Instrument Cost

• $1,500–$25,000