3. 3
• Purite designs, develops and manufactures
water purification systems
• For use in applications in laboratory,
healthcare and industry.
• We specialise in a wide range of technologies,
including:
• ion exchange carbon filtration
• reverse osmosis
• electro-deionisation
• ultrafiltration.
About Purite
4. 4
Water Standards
• Water is one of the most important raw materials used for
research & development, laboratory and production
applications.
• Quality of raw water drawn from the mains or local
borehole supplies can be extremely variable.
• Measures need to be in place to purify the water to suitable
standards.
• Specific water purity standards have been developed over
the years.
• Quality of water required is linked to application.
5. 5
Water Standards
BS EN ISO 3696:1995
• Three standardised grades, expressed in terms of conductivity
as below:
Grade Microsiemens(MIN) Resistance(MIN) pH Si(ppb)max
1 0.1 10 N/A 10
2 1 1 N/A 20
3 5 0.2 5-7.5 N/A
6. 6
Water Standards
ASTM D1193-06 (2011)
• Four standardised types, expressed in terms of conductivity as
below. Further graded on bacterial, Endotoxin requirement as
more application specific:
Type Grade Microsiemens(MIN) Resistance(MIN) pH Si(ppb)max cfu/ml max Endotoxins Eu/ml max
I 0.056 18 3
I A 0.056 18 3 10/1000 0.03
I B 0.056 18 3 10/100 0.25
I C 0.056 18 3 100/10
II 1.000 1 3
II A 1.000 1 3 10/1000 0.03
II B 1.000 1 3 10/100 0.25
II C 1.000 1 3 100/10
III 0.250 4 500
III A 0.250 4 500 10/1000 0.03
III B 0.250 4 500 10/100 0.25
III C 0.250 4 500 1000/100
IV 5.000 0.2 5-8
IV A 5.000 0.2 5-8 10/1000 0.03
IV B 5.000 0.2 5-8 10/100 0.25
IV C 5 0.2 5-8 100/10
Most people refer to ASTM standards, but interpretation varies
7. 7
Water Standards
• Other specialised standards exist for industries such as the
electronics and semiconductor industry where specific metal
specifications need to be met.
• The healthcare industry also has its own set of standards.
8. 8
Applications
• Type IV
Non-Critical work. Water baths, autoclave and
disinfector feed, environmental chambers, plant growth
rooms. Type 1 production.
• Type II/III
General Lab use. Glassware rinsing, media preparation,
pH solutions & buffers, reagent preparation. Type 1
production.
• Type I
Water critical applications. Clinical Analysers, HPLC,
GC, AA, ICP-MS, advanced analytical techniques,
Tissue Culture, Life Science, Molecular Biology.
QUALITY - LINKED TO APPLICATION
9. 9
Technology-RO
• Latest RO technology can improve water quality and lab
productivity.
• RO is a powerful method of producing purified water for a
wide range of laboratory duties.
• Modern units will pre-filter and de-chlorinate the raw
water feed, then pass through semi permeable polymer
RO membranes.
• The permeate passes through the membrane which
removes up to 98% of the minerals and salts, plus
virtually all colloids, microorganisms, endotoxins and
organic macromolecules.
10. 10
Technology
Deionisation
• Deionisation can be used purify water.
• It uses a mixture of resins to remove anionic and cationic
contaminants from the feedwater, exchanging with active
hydrogen and hydroxyl ions, which combine to form water
molecules.
• Deionisation can be used alone to produce Grade 1 (>10
MΩ) water, but is uneconomic at high TDS levels or for high
usage (>100l/day).
• Generally the most efficient treatment is a combination of
RO and Deionisation.
11. 11
Technology
Laboratory systems
• Specification should begin with consideration of the
standardised grades of water purity.
• Having established the level of purity required, then the
volume needed should be assessed.
• This is followed by the decision to install a centralised or
stand-alone unit.
• Choice is dictated by overall costs and the operational
demands of each option.
• Purite has developed a range of stand-alone units designed
to meet the needs of the modern laboratory
12. 12
Quality Considerations?
QUALITY - LINKED TO APPLICATION
• RO WATER (5 – 35 µs) – Feed for Humidifiers, Autoclaves,
Lab ring mains.
• DI WATER (1 – 10 MΩ) – Glassware rinsing, Reagent make-
up, Media prep, General Lab use.
• HPLC GRADE WATER (>10 MΩ) – HPLC, Ion
Chromatography, Atomic Adsorption, Analyser feed.
• ULTRA PURE WATER – (18.2 MΩ) – Tissue Culture, Life
Science, Molecular Biology.
35. 35
Product Selection
Considerations
• What flow rate is required? (litres/hr or litres/day)
• What is the demand pattern? (how much needed at once)
• What quality of water is required? (Grade or Type)
• What is the end use application? (General Lab etc)
• What quality is the feedwater? (TDS)
• What is the mains pressure? (bar or psi)
36. 36
Contact Purite
Purite Ltd
Bandet Way
Thame, Oxon
OX9 3SJ UK
Tel: +44 (0)1844 217141
Fax: +44 (0)1844 218098
Email: mail@purite.com
www.purite.com