Water Quality Standards & Applications

What is pure water?

Water, mechanically filtered or processed to remove impurities and make  it suitable for use.

Impurities:

Inorganic, organic or biological.

Purified water parameters

Parameter Control method
Inorganic ion concentration Conductivity measurement
Total organic carbon Photooxidation, UV measurement
Bacteria concentration Incubation, growth, examination
RNase/Endotoxin concentration Specific laboratory tests

Properties of water

Water type Contamination Configuration
Inorganic Organic Bacteria RNase
Distilled (RO) water Moderate Moderate Undefined Undefined “RO”
Pure water Low Moderate Undefined Undefined “Pure”
Analytical grade Very low Low Low Undefined “Trace”
HPLC grade Very low Very low Very low Moderate “HPLC”
Bio grade Very low Very low Very low Very low “Bio”

Main contaminants

Specification of laboratory water ISO 3696 Specification of laboratory water ASTM (D1193-91)
Grade 3 (>0.2 MΩ*cm, < 5 μS/cm)
  • Used for general laboratory work - glassware washing, autoclave filling, heating baths – and as feed to Grade 1 systems
Grade 2 (>1 MΩ*cm, < 1 μS/cm)
  • Used for sensitive analytical methods (Flame AAS)
  • Also referred to as “Pure water”
Grade 1 (>10 MΩ*cm, < 0.1 μS/cm)
  • Used for ICP-OES, ICP-MS, high performance liquid chromatography, molecular biology
  • Also referred to as “Ultrapure water”
  • Splits into subgrades depending on application
 Type IV (>0.2 MΩ*cm, < 5 μS/cm)

Type III (>4 MΩ*cm, < 0.25 μS/cm)
  • Used for general laboratory work - glassware washing, autoclave filling, heating baths – and as feed to Type I systems
Type II (>1 MΩ*cm, < 1 μS/cm)
  • Used for sensitive analytical methods (Flame-AAS)
  • Also referred to as “Pure water”
Type I (>18 MΩ*cm, < 0.056 μS/cm)
  • Used for ICP-OES, ICP-MS, high performance liquid chromatography, molecular biology
  • Also referred to as “Ultrapure water”
  • Splits into subgrades depending on application

International Water Quality Standards

Inorganic ions

Successfully removed by reverse osmosis and deionizing resins.

Organic molecules

Partially removed by activated carbon and reverse osmosis
(large molecules mostly).

Fully removed by photooxidation and polishing.

Organic molecules

May grow on resins, inner surfaces of the tubes.

Should be eliminated by UV lamp and filtered by 0.22 μm filter right at the dispensing port.

RNase/Endotoxins

Critical for molecular biology applicaitons.

Removed by point-of-use ultrafilter that needs periodic replacement.

Laboratory Applications

We offer water treatment solutions for a wide range of laboratory applications. The list below helps you find the right water treatment system for your application. Please feel free to contact us for further information.

Atomic Absorption Spectroscopy

In Atomic Absorption Spectroscopy techniques, the analysis is performed either by evaporating the sample in flame (FAAS) or in a graphite furnace (GFAAS).

To ensure precision and accuracy of measurements, Grade 2 water is suitable for FAAS analysis, while ultrapure, Grade 1 water is required for GFAAS due to higher sensitivity and lower detection levels of the method.

Suitable products:
Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Compact Pure
Integrity+
Connect
Connect LT
Onsite+

Chromatography

Liquid Chromatography (LC)
High-Performance Liquid Chromatography (HPLC)
Ultra-High-Performance Liquid Chromatography (UHPLC)
Gas chromatography (GC)
Ion Chromatography (IC)

Suitable products:

Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Integrity+
Connect
Connect LT
Onsite+

General Laboratory Water

Glassware washing
Autoclave Filling
Steam Generators

Suitable Products:
Q-Front
Compact RO
RADIX RO
Compact Sterifeed

Molecular Biology

Laboratory water for Molecular Biology applications require the highest purity levels. Typically, nuclease-free Grade 1 water should be used. 

Suitable Products:
Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Integrity+
Connect
Connect LT
Onsite+

Clinical Biochemistry

Clinical biochemistry is concerned with methodology and interpretation of a wide range of in vitro chemical and biochemical tests performed on body fluids and tissues, to support diagnosis, treatment and monitoring of disease. The most important aspect of water for automated pathology analysers is reliability, and therefore must be compliant with a the appropriate water quality standards such as CLRW. The CLRW resistivity specification of >10 MΩ x cm.

 

Suitable products:
Compact Pure
Compact EDI Pure
RADIX EDI

General Chemistry

Electrochemistry
Wet chemistry
Spectrophotometry

Suitable Products:
Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Integrity+
Compact Pure
Compact EDI Pure

ICP-MS and ICP-OES

Inductively coupled plasma atomic emission spectroscopy (ICP-OES)

Inductively coupled optical emission mass spectrometry (ICP-MS)

Gas Chromatography - Mass Spectrometry (GC-MS)

Suitable Products:

Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Integrity+
Connect
Connect LT
Onsite+

Microbiology

For general purposes in a microbiology laboratory, for example, media preparation, Grade 2 water is perfectly suitable, while more sensitive applications require the use of ultrapure, Grade 1 water.

 Suitable Products:

Gradus
Q-Front N
Q-Front
Q-Front EDI
B300
B310
Crystal EX
Integrity+
Connect
Connect LT
Onsite+