Types of Laboratory Water and its Usages
Often laboratory grade water is taken for granted in a day to day lab use. This is very much noticed in recent years and there is a growing interest to know which water to use for which application. There is a curiosity among lab scientists, am I using the right quality of water.
Wonder that water used in lab can cause deviations or impacts in our day to day laboratory work? Most of the scientists deny agreeing to this. But the fact is that, if right water quality is not used, it will interfere and cause variations in the analysis.
You may be curious to know that, does there exist any types in water quality to be used in lab. You might have come across various scientific literature mentioning about different grades of laboratory water used as per their applications. You got it right, that lab grade water to be selected and used depends on the nature of the work you are involved in.
Usually there is a tendency to use water in any of the application as Water is the universal solvent, but the mystery lies in the quality you select to get desired results based on the sensitivity of your instruments and applications.
In general, laboratory grade water is classified as Type I, Type II and Type III water. These grades are classified based on the purity of water, where Type I water has the highest purity and Type III has the least.
Type I water, the purest grade of lab water, is also referred as ultrapure water. Type I water is recommended to be used in highly critical applications like HPLC, Mass Spectrometry, trace elemental analysis and biotechnology.
Type II water, also known as ‘Pure Water’ is a recommended source of pre-treated water to feed your Type 1 ultrapure systems. Type II water is usually recommended for use in buffer preparation for dissolution, microbiology media preparation or sometimes in biochemistry analyzers in diagnostic industry. This Type II — pure water can also be used for the preparation of reagents for chemical analysis.
Type III water, commonly referred as instrument feed water is the lowest form of lab water. This type of water is produced using Reverse Osmosis (RO) that removes about 90–99% of contaminants. Type III water is recommended to be used in Glassware washers, humidity chambers or autoclaves.
When you refer the specifications for these grades of water from global guidelines like International Organization for Standardization(ISO), American Section of the International Association for Testing Materials (ASTM), Clinical & Laboratory Standards Institute(CLSI), as they all differ in the purity with respect to the levels of conductivity, Total Organic Carbon (TOC) and bacterial levels.
Also, not necessarily that across the global guidelines this terminology Is used. There are terminologies like grades or application driven titles like reagent or analytical grade water is used in the industry. Beware, when you are looking for Pharma or Biopharmaceuticals do not forget to refer to pharmacopeia’s like United States Pharmacopeia (USP), European Pharmacopoeia (EP), Japanese Pharmacopoeia (JP) or British Pharmacopoeia (BP). In these pharmacopoeias, laboratory grade water is often referred to as purified water.