The freezing point depression osmometer is an

osmometer An osmometer is a device for measuring the osmotic strength of a solution, colloid, or compound. There are several different techniques employed in osmometry: * Vapor pressure osmometers determine the concentration of osmotically active particle ...

that is used in determining a solution's

osmotic concentration Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L ...

as its osmotically active aspects depress its

freezing point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depe ...

. Osmometry further involves other techniques that including membrane osmometry which determines the osmotic pressure of solutions and

vapor pressure osmometry Vapor phase osmometry (VPO), also known as vapor-pressure osmometry, is an experimental technique for the determination of a polymer's number average molecular weight, Mn. It works by taking advantage of the decrease in vapor pressure that occurs w ...

which assesses the concentration of particles that minimizes a solution's

vapor pressure Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phase ...

and melting as well as freezing points of

aqueous solution An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would ...

s. Freezing point depression osmometry is, however, the most preferred in distinct contexts. In the past, it has been used to assess the osmotic strength of a

colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others exten ...

and solutions. The osmometer uses the solution's freezing point depression to establish its strength. It is used to determine the level of osmotically appropriate body fluid in various chemicals dissolved in the blood using the relationship which a mole of dissolved substance reduces the freezing point of water by . Being efficient, freezing point depression osmometer is used in various medical practices, including pharmaceutical manufacturing, quality control laboratories, and

clinical chemistry Clinical chemistry (also known as chemical pathology, clinical biochemistry or medical biochemistry) is the area of chemistry that is generally concerned with analysis of bodily fluids for diagnostic and therapeutic purposes. It is an appli ...

Method

Freezing point depression osmometers will be utilised to determine a solution's osmotic strength. It is the most preferred method which is applicable in performing various activities in the medical field. It is used in assessing the osmotic strength of colloids, as well as solutions. The freezing point depression osmometer operates by using the solution's freezing point to determine the concentration of the solution. It uses a nanolitre

nanometer 330px, Different lengths as in respect to the molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re, ...

, a device that facilitates the establishment of the solution's melting and freezing points. The determination of the freezing and melting points involves four distinct steps. These are; calibration, loading, deep freezing, and determination. By determining the solution's freezing point, it is possible to establish the number of particles in it, an aspect that allows the determination of its concentration. When particles are dissolved in a solution, its freezing point is lowered compared to that of the original solvent. A further increase in the solute decreases the freezing point even further. The freezing point depression osmometer uses the solution's freezing point to establish its concentration. The freezing point depression osmometer is calibrated using standards that are within the solution's osmolality range.

History of use

The use of osmometers began in the late nineteenth century after van’t Hoff won a

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfre ...

for his research and discovery that the relationship between the osmotic pressure of dilute colloid solutions and concentration was consistent with the

ideal gas law The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first st ...

. Since then, osmometers have been used to measure the osmotic strength of a dilute solution at different levels of concentration. The historical use of the method has been validated by Guerrero et al. in an analytical study, in which they tested their urine osmolality of 1,991 dogs. The study discloses the past achievement of professionals where using the approach, they managed to measure canine and, in the end, established intervals and the impacts of sex, age, as well as, reproductive status. The historical use of the method is further disclosed by Hale et al. who elaborate its distinct advantages over the other conventional concentration osmometers, which rely on the osmotic pressure profile.

Current usage in medical fields

Freezing point depression osmometers are applied in various areas in the medical field. The approach is used in determining the colloidal aspects in solutions. elaborates that the method is advantageous as compared to other conventional approaches, an aspect that has increased its application in the medical sector. In the present day, the method is applied in among other areas, in measuring osmolarity in lens care solutions as well as eye drops, promoting eye health. It is further used in clinical chemistry, pharmaceutical and quality control laboratories where it facilitates different processes. As compared to the other methods, the freezing point depression osmometer has a high level of precision and accuracy, making its application in clinical practices safe. It is applied in various processes that involves the manufacturing of drugs. Urine osmolality is also used to measure urine concentration accurately thus determine renal function and body fluid homeostasis.

Evaluation on its use

Osmometry is preferred in among other areas, pharmaceutical, quality control laboratories, and in clinical chemistry where it facilitates the establishment of precise measurements, hence facilitating the various medical practices. It's preference further result from its easy and fast means to determine the

osmolality Molality is a measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent. This contrasts with the definition of molarity which is based on a specified volume of solution. A commonly used unit for molal ...

in aqueous solutions. The freezing point depression osmometer is largely used in the medical sector where its preference is promoted by its precision. It is used in medical clinics where it is applied in distinct pharmaceutical practices. These include among other activities, the development of lens care solutions and eye drops where the technique is applied to develop the proper development of a proper solution to promote eye health. Indeed, medical professionals using the method have achieved significant success both in the past as well as in the present day.

External links

General Chemistry principles, patterns and applications

References

{{Chemical solutions Measuring instruments Membrane technology