20 Feb

Wireless Weather Stations

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Professional Weather Stations for use in schools, labs and industrial applications.  This instrument is designed to monitor conditions, forecast weather, and check environmental air parameters.  The unit displays temperature, humidity, dew point, barometric pressure/pressure trend, weather forecast, wind direction/speed, wind chill, rainfall amount, and clock/calendar.  The model displayed on the left has a serial data output which  permits linking to a computer for storing all information.  Stored data  can then be placed into a permanent weather database for  generating analysis, and studying weather trends.

A complimentary instrument in the study and monitoring of Meteorology is the Anemometer/Thermometer which measures air velocity and temperature.  Readings are updated instantaneously and has a memory function which will recall the highest and lowest readings.

OpticsPlanet offers these and similar tools which prove to be beneficial for use in both the laboratory and classroom environment.  Though I’m sure the novice hobbyist would also find them both educational and entertaining.

Please feel free to contact any of our knowledgeable staff for additional information or for assistance in selecting the best weather station for your needs.

Stephen Gonshorek

17 Feb

An Easy Start to Pure Lab Water

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Where do you start for a laboratory water treatment system?  Especially if you have a small laboratory.  Initial water treatment in the lab could start with a water pre-filter to remove particulates followed by a reverse osmosis system.  This is a simple way to have Type III water which is suitable for many of your laboratory procedures.  RO water can also be feed water for Type I ultra purification systems.  Reverse Osmosis removes >94% of dissolved ions and >99% of suspended solids, bacteria and pyrogens.  Reverse osmosis produces Type III water ready for further purification to Type II or Type I water. The amount of contaminants removed depends greatly on the feed water for the RO system.

From Inspectapedia.com

From Inspectapedia.com

Osmosis is the tendency of water molecules to move across a semi-permeable membrane from the purer side of the membrane to the less pure side; this is how cells exchange water and nutrients.  Osmotic pressure is the pressure of the water molecules on the membrane from the purer side.    In reverse osmosis pressure is applied – greater than osmotic pressure – to the less pure side of the membrane forcing water across the membrane and leaving behind most of the inorganic ions and other contaminants.

Particulates, dissolved organics, and Chlorine are damaging to reverse osmosis membranes and many RO units have a pre-filter and an activated carbon filter.  Reverse osmosis has a slower flow rate than other water treatment technologies so it is necessary to store the RO water in a tank.  A pump may also be necessary to provide the required flow rate from the RO tank to subsequent water treatment units.

RO is a good first step in a water polishing system; the quality of RO water protects polishing systems such as deionizing cartridges.  RO water quality is sufficient for many routine laboratory needs.

 

Robin Prymula

13 Feb

Brushes for Cleaning Test Tubes

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4831777The right tool for the right job!  Test Tube Brushes seem to be one of those items you don’t really think about until you need it.  I recently received orders from several labs.  In each case, the tech ran out or had used the last remaining brush they had, beyond the life of the bristle.  Needless to say, I end up placing some rush orders, which prompted me to create this blog as a friendly reminder to those of you who haven’t checked your stock of brushes in a while.

Standard lengths range from 8″ to 13″ with brush diameters from 3/4″ (1.9 cm)  to 1-3/8″ (3.5 cm).  Though there are longer and wider brushes available, including beaker and centrifuge brushes, which I’ll address in a future blog.  Choice of bristle’s are nylon and natural and most come in packs of 10, which should keep you going for awhile.

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Again, these brushes are ideal for cleaning test tubes and narrow mouth glassware. Rounded tuft at tip facilitates cleaning and protects the glassware.

The brush pictured to the right is an example of a test tube brush that has a Tufted End.

Stephen Gonhorek

10 Feb

Your Lab Water is Important

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What type of water do you need in your day to day lab work?  Water types used in the laboratory can be Type I water, Type II, Type III – determined by the levels of impurities.  If you are washing glassware, autoclaving, or you need feed water for other purification systems, Type III water is appropriate.  Type II water is sufficient for your test methods where the presence of bacteria will not interfere, or for microbiology where your preparations are to be sterilized.  Type I water is necessary where the presence of small amount of bacteria and endotoxins will interfere with your work

From Thermo Scientific

From Thermo Scientific

and where the presence of  small amounts of electrolytes will cause interferences.

Here are some useful definitions:

Particulates – suspended particles which could be debris from piping, sit, colloids. . . this is what will make water turbid, cloudy.  Microfiltration, distillation, and reverse osmosis will remove particulates.

Resistivity (conductivity) – The tendency of the water to conduct electricity in the absence of added ions.  The unit for resistivity is megohm-centimeter or MΩ-cm.  Units for conductivity are microSiemens/centimeter or μS/cm another unit is the reciprocal of ohms, the mho; 1 mho/m = 1 S/m.  A measurement of dissolved inorganics, largely Calcium and Magnesium which make hard water, although other inorganics such as Sodium and Chloride can be present as well.  These can be removed by deionization or to a lesser extent by reverse osmosis.

From Elga LabWater

From Elga LabWater

Total Organic Carbon – Dissolved organic molecules measured in parts per million, ppm, for feed water and parts per billion, ppb, for treated water.  The organic molecules come from decayed plant and animal material, pesticides, plasticizers from piping, and other sources.  Carbon filtration, distillation, as well as UV oxidation can remove dissolved organics.

Microorganisms and endotoxin – Bacteria enter the water treatment system through feedwater and by exposure to air.  The system must be designed to inhibit growth of the microorganisms.  Endotoxins are molecules released by the bacteria or produced when the bacteria dies.  Both Bacteria and endotoxins are removed by distillation and ultrafiltration at point of use.

ASTM Standards for Reagent Water

Measurement (Unit)                       Type I                   Type II                  Type III

Colloids – Silicia/μg/ml                   <3                          <3                          <500

Resistivity (MΩ-cm) at 25° C         >18                      >1                         >4

Total Organic Carbon (ppb)           <50                       <50                       <200

The ASTM standards are further subdivided into A, B, and C.

Measurement (Unit)                                                     A                            B                            C

Heterotrophic Bacteria Count (CFU/ml)                10/1000               10/100                1000/10

Endotoxin (units per ml)                                             0.03                      0.25                      n/a

Robin Prymula

06 Feb

Vortex Mixers

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A Vortex Mixer is actually a simple devise found in most laboratories. The phrase “Shaken not Stirred” comes to mind, though not sure how functional this would be for your next cocktail party. All kidding aside, it is designed to mix small vials of liquid. It consists of an electric motor, vertical drive shaft and a rubber cupped piece which is mounted slightly off-center. As the motor runs, the rubber piece oscillates rapidly in a circular motion. When you touch the vial or container to the rubber cup, the motion that is being created is transmitted to your container, creating a “vortex”.

The mixer is commonly found in most bio-science labs. Cell culture and microbiology labs will use the device to suspend cells, whereas a biomedical or analytical lab would use it to mix reagents and assays. The analog vortex mixers have a variable speed control from 300–3200rpm, which allows low rpm startup for gentle shaking or high-speed mixing for vigorous vortexing of samples. Units can be operated in touch mode when depressing the cup head or in a continuous mode.8082784

Muiltitube Vortexers, like the one pictured to the right, are designed to hold up to 50 tubes at one time. The top of the tubes are held securely, while the bottom are allowed to move freely. This vortexer is supplied with a foam rack to accommodate 12mm tubes. There are foam racks for other tube sizes that are readily available as an accessory.

Stephen Gonshorek

03 Feb

Beer’s Law

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No it’s not a law about beer as in ale. Beer’s law, or the Beer-Lambert law describes the relationship between absorbance of light by a substance, the distance the light travels through the substance, and the concentration of the substance.

A=elc

Where A* is absorbance; e is the molar absorptivity of the substance in L/mole cm; l is the length the light travels through the substance in cm, l is generally 1cm; c is the concentration of the substance in moles/L.  Colored solutions absorb in the visible region of the electromagnetic spectrum but proteins and DNA absorb in the ultraviolet region.

From Columbia University Science Teacher Program
From Columbia University Science Teacher Program

Absorbance is a unitless value so we refer to absorbance units.  If e is known, the concentration of a substance in solution can be determined. An unknown concentration may also be determined by comparing the absorbance of a known (standard) concentration of the substance with the absorbance of the unknown concentration.

For sample determinations a standard of known concentration of the analyte of interest is prepared and the absorbance is determined.  The absorbance of the unknown sample is then determined.

A Std      A Unk

Conc. Std   =  Conc. Unk

The response of absorbance vs. concentration is linear through 2 absorbance units but above 2 absorbance units linearity falls off.  Samples and standards must be diluted so that absorbance falls between 0 and 2 absorbance units.

Absorbance can be measured using an instrument as advanced as a double beam scanning UV/VIS absorption spectrophotometer or as simple as in colorimetry. The principle of absorbance is also utilized in other instruments such as HPLC and LC detectors.

*A=-log(I/Io) where Io is the initial intensity of the light beam and I is the intensity of the light beam after passing through the sample.

Robin Prymula

30 Jan

Safety Caps

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OfficiallyLicensedNFLV-GardProtectiveCaps_000060001900001100Though not exactlly related to laboratory geer and might be considered a bit of a reach, I thought these were pretty neat and worth sharing as we all prepare for Super Bowl 2014

MSA, manufacturer of Safety Equipment and in this case, Safety Caps, offer a line of NFL  V-Guard Helmets with your favorite team logo.  What a great way to support your team and at the sametime, protect yourself from flying beer bottles while attending the game.  (Sorry, Bad Joke).

The helmets offer superior, quality comfort and more workers would be inclined to wear them.  These stylish Specialty V-Gard ® Caps feature MSA’s 1-Touch® Suspension and slots to accept MSA V-Gard Cap Accessories. The caps are available in eye-catching logos of every NFL team.

New Picture (2)Chicago New Picture

Applications required for wearing protective head gear include:

  • Food Processes
  • Asbestos Abatement
  • Painting

Certifications include:

ANSI/ISEA Z89.1-2009 (Class E, Type I)  CSA Z94.1-2005 (Class E, Type I)

For a list of available logo’s which seem to cover every NFL Team and assistance in placing your order, please contact any of our associates here at OpticsPlanet.

Stephen Gonshorek

27 Jan

Coulter Counter

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Beckman CoulterThe Coulter principle is used to count particles suspended in an electrolyte, in a flow cell this would be flow cytometery.  This principle applies to cell counting in hematology as well as any small particle counting.  Not only are the cells and particles counted but the sizes of the cells and the distribution of the sizes are also determined.  The suspended particles are passed through an orifice and  an electric charge is passed along the orifice.  The change in impedence as the particles pass through is directly related to the volume of the particle.  Coulter counters have been available from Beckman Coulter since 1997.  A new automated electronic cell counter based on the Coulter principle is being marketed Moxi-Zby Orfl0 and is called the Moxi-Z.

The Coulter principle is a more accurate way to count cells than visually.  Also the cells do not need to be dyed as they do for cell counting instruments based on visualization.  Particle counters using the Coulter principle can count any type of small particles (5 – 25um), not just cells.  The particles must be suspended in a conducting solution.

 

Robin Prymula

23 Jan

Windguards

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10006530

opplanet-jackson-safety-windgard-aa-8-red-14496-mainWell it is that time of year when dealing with the winter elements can be a challenge. Given the fact that the temperatures here in Chicago have been in single digits with windchills -20 degrees, sales of the Kimberly Clark  Windguards  by Jackson Safety are up.  They’re going like Hot Cakes.  Excuse the pun.

Although not very fashionable, this will protect you from the elements.

 

Designed to keep the wind out and at the same time, traps warmth. Knitted, flame-resistant, treated polyester meets 16 CFR 1610, Class 1 requirements. High-visibility color. Fits over most safety caps and full-brim styles. Warmth for temperatures ranging from 32 to 0° F (O to –20° C).

10011264

Again this is ideal for very cold environments.  The Full head & neck liner with wide wraparound collar are designed to be Universal for fitting all head sizes Leather/Nomex® tabs attach to hard hats which provides protection from electrical arc energy exposure.  The 100% Nomex® outer shell maintains FR protection throughout the life of the product.

Flame resistant inner shell maintains flame resistance through 25 industrial washes or 50 domestic washes.
The Red Plaid Shirt is optional. (just kidding).

For additional information or to place an order, please contact our staff here at OpticsPlanet.

Stephen Gonshorek

 

 

20 Jan

Ultra High Performance Liquid Chromatography: UPLC

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Ultra Performance Liquid Chromatography is related to HPLC (High Performance or High Pressure Liquid Chromatography) but uses smaller particle sizes (less than 2 μm.) and smaller diameter columns.  The efficiency of HPLC separation is inversely related to particle size.  Unfortunately the smaller the particle size the higher the back pressure.  UPLC Systems are now being designed with columns and mobile phase pumps to accommodate this higher pressure (typically 20,000 psi vs. 6000 psi for HPLC).   The advantages of UPLC is shorter run times (4 minutes vs. 30 minutes)  and increased separation with taller and narrower peaks.  The short run times indicate how small the column volumes are.  The instrumentation must also be designed with much smaller volumes; for example injection volumes go from 20µl to less than 2µl.  Specialty fittings (ferrules, nuts) have been developed to withstand the higher pressures in UPLC.  The high pressures require extremely high quality tubing with specially cut and polished ends.  The detectors – UV, fluorescence, evaporative light scattering (ELS) – must be designed with smaller volumes.  In HPLC peak widths are typically 20 seconds so a data sampling rate of 1 point per second is suitable; with UPLC peak widths of only 1 0r 2 seconds the data sampling  rates must be increased to up to 40 points per second for reproducible integration.  The UPLC systems price is 40 to 100% more than HPLC systems but the increase in sample throughput is 10 times.  For a lab considering another HPLC system to accommodate higher sample loads the UPLC may be the most cost effective instrumentation.  In labs where HPLC is used only occasionally or the detection limits of conventional systems are adequate the UPLC system would be not be the cost effectiveChromatogram choice.

Robin Prymula