lab glass cleaning
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Advice and tips for clean and residue-free lab glass and laboratory equipment - cleaning agents and cleaning processTRANSCRIPT
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Lab Glass Cleaning.com
Advicefor clean and residue freeresidue-freelaboratoryequipment
© Dr. Weigert & DURAN Group 2012
Good practice– type of glass.com
Good practice type of glass
Selection of right types of glass
a high quality of the raw materials and their i icomposition
wall thickness distribution in order to attain a good resistance to temperature and g pchanges in temperature, high level of mechanical stability
a very high hydrolytic resistance a very high hydrolytic resistance (corresponds to class 1 according to ISO 719).
very small expansion coefficients, a high level of resistance to quick changes in temperature
© Dr. Weigert & DURAN Group 2012
Good practice– conformity to standards.com
Good practice conformity to standards
• Why should attention be paid to conformity to standards?
standards set the properties and standards set the properties andgeometries for laboratory glass products -> products can be still be obtained with thesame characteristics and dimensionssame characteristics and dimensions even after many years
characteristics which are decisive for safety such as distribution of wall thickness in beakers, are given in the standards for many articles
© Dr. Weigert & DURAN Group 2012
Good practice– instruction for use.com
Good practice instruction for use
• What is important when selecting a glass item for use?
before each use the glass surface should be before each use the glass surface should be checked for damage such as scratches, cracks or chips
l h ld l b d h h vessels should only be used when they are in a flawless condition, this is particularly important for work under pressure or at high temperatures
damaged glass may not be used for safety reasons.
© Dr. Weigert & DURAN Group 2012
Cleaning – cleaning process.com
Cleaning cleaning process
The advantage and disadvantages of
• manual cleaning greater risk of injury
slower and less economical when there are lots of items to be washedare lots of items to be washed
time consuming when the laboratory appliances have a complex geometry
is clearly quicker if only single laboratory glass items are being cleaned
flexible in terms of duration of cleaning flexible in terms of duration of cleaning and selection of cleaning agent
© Dr. Weigert & DURAN Group 2012
Cleaning – cleaning process.com
Cleaning cleaning process
Advantages and disadvantages of• cleaning in a washer/disinfector
reduced breakage risk reduced breakage risk
reduced risk if injury
saves staff resources
quicker and more economical for large quantities of items to be washedwashed
inflexible in terms of duration of cleaning and selection of cleaning agent
© Dr. Weigert & DURAN Group 2012
Cleaning – type of soiling.com
Cleaning type of soiling
Type of soiling
• Organic soiling
peptides/ proteins, fats/oils, carbohydrates/ polysaccharides, organic colourings pigment residuesorganic colourings, pigment residues and felt tip residues, resins and paraffin
© Dr. Weigert & DURAN Group 2012
Cleaning – type of soiling.com
Cleaning type of soiling
Type of soiling
• Inorganic soiling g g
carbonates, salts, metal oxides, watery solutions of inorganic acids(HCl H SO )/(HCl, H2SO4)/ alkali (NaOH, KOH), salt solutions(NaCl, NaNO3, FeCl2 etc.)
© Dr. Weigert & DURAN Group 2012
Cleaning – type of soiling.com
Cleaning type of soiling
Type of soiling
• Microbiological residueg
growth media, cell cultures and tissue residues, nutrient broth,
i imicroorganisms
© Dr. Weigert & DURAN Group 2012
Cleaning - cleaning agents.com
Cleaning cleaning agents
Which cleaning agents are suitable for which soiling?
• Alkaline cleaning agents it bl f th d t i d l are suitable for the denaturing and removal
of residues which contain protein, fat and carbohydrates
• Acid cleaning agents are effective against inorganic salts,
lime and other carbonates.
• Bleaching agents help with the removal of paints and with disinfection.
© Dr. Weigert & DURAN Group 2012
Cleaning - cleaning agents.com
Cleaning cleaning agents
• What requirements must a cleaning agent meet? The selection is linked to the type of soiling to
b d d th f k diti (tibe removed and the framework conditions (time, material properties and mechanical system, qualityof water)
fundamental requirements:
good ability to remove dirt
high dirt carrying capacity
• Which resources can be used?
abrasive materials (steel wool) high dirt-carrying capacity
suitable for most surfaces
good rinsing properties
must not be used -> these will cause surface damage to the glassg g p p
not hazardous to health
very cost-effective
soft sponges, cloths and brushes are suitable
© Dr. Weigert & DURAN Group 2012
environmentally friendly
Cleaning – parameters of cleaning.com
Cleaning parameters of cleaning
• Chemistry (=cleaning agents) helps with the decomposition of dirt
t d th i lificomponents and thus simplifies the removal of dirt from surfaces
the surfactants contained in cleaning agents improve the wetting of the item to be cleaned and the dirt-carrying capacity of the watercapac ty o t e ate
the selection of the cleaning agent to be used depends on the dirt to be removed the material of the items to beremoved, the material of the items to becleaned and the quality of water used for automated cleaning
© Dr. Weigert & DURAN Group 2012
Cleaning – parameters of cleaning.com
Cleaning parameters of cleaning
• Temperature high temperatures can accelerate physical,
h i l d ti dchemical and enzymatic processes and thus benefit removal of contaminations
temperatures which are too high can,
however, reduce enzyme activity
Another disadvantage of excessive temperature i th i f b i id t i d iis the conversion of carbonic acid contained in the water to carbonate via hydrogen carbonate which is then precipitated as a poorly soluble compound with the water hardening salts magnesium and calcium. This results in stubborn ‘lime deposits’.
© Dr. Weigert & DURAN Group 2012
Cleaning – parameters of cleaning.com
Cleaning parameters of cleaning
• Time an extended reaction time for the
l i l ti k th lcleaning solution makes the removal of dirt from the surface easier due to better swelling of the contaminants and a stronger chemical decompositionof the dirt components
© Dr. Weigert & DURAN Group 2012
Cleaning – parameters of cleaning.com
Cleaning parameters of cleaning
• Mechanics The use of mechanical agents such as the
f b h duse of brushes or pressurized water jets enables bonding forces between dirt and surface to be overcome so that dirt can then be removed more easily.
Chemistry temperature time and mechanics are the four components Chemistry, temperature, time and mechanics are the four components of the so-called Sinner’s Circle which describes the mode of action of the cleaning process and which was named after the chemist Dr. Herbert SinnerSinner.
© Dr. Weigert & DURAN Group 2012
Cleaning – Dr. Sinner´s Circle.com
Cleaning Dr. Sinner s Circle
Dr. Sinner’s Circle
Each parameter is variable in size. However, if one factor is changed this will affect the size of at least one other factor if the cleaning performance is to remain the same. This means that a longer reaction time is necessary if there is a lower temperature in the rinsing process for example. A reduced parameter is thus compensated by the increase of another.
© Dr. Weigert & DURAN Group 2012
Cleaning – quality of water.com
Cleaning quality of water
Quality of water
defines
• microbiological factors (germ count)
• the degree of water hardness, given in °GH (German hardness) (magnesium and calcium ions in the water )(magnesium and calcium ions in the water )
If water with a high degree of hardness is used for cleaning, significant residues may be deposited on the cleaned surfaces
Depending on the water quality (e.g. deionised water or softened water) different effects are achieved in combination with the used cleaning agents. These affect the material compatibility and the cleaning results.
© Dr. Weigert & DURAN Group 2012
Advice and Tips• How can laboratory glass be stored correctly
.com
Advice and Tips• How can laboratory glass be stored correctly
whilst saving as much space as possible?
• Marking – what has to be observed?
• How can stubborn residues be avoided?
• How should the glass be disposed of?
• What should you know about volumetric• What should you know about volumetric glassware?
• How should you clean cover glass and slides?
All this and more at :
www.labglasscleaning.com
© Dr. Weigert & DURAN Group 2012
Laboratory Glass Cleaning.com
Laboratory Glass Cleaning
From experts for experts –p p© Dr. Weigert & DURAN Group 2012
www.labglasscleaning.com
Pictures by Karin Gerdes
© Dr. Weigert & DURAN Group 2012
Pictures by Karin Gerdeshttp://www.karingerdes.de