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The Environics, Inc. Post

The Environics, Inc. Post

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Happy Thanksgiving!

 

A reminder that we will be closed tomorrow and Friday as we celebrate Thanksgiving with our loved ones.

A very Happy Thanksgiving to all of you!

fall foliage resized 600

 

Gas Chromatography and Calibration Standards - A Review

 

Today, we reshare one of our most popular and most often referenced posts.  We will focus on gas chromatography (or GC), a technique used by many of our existing customers in a wide variety of fields.

To state it simply, GC is a method used to separate, identify and quantify chemical compounds.  A mobile phase containing the sample is passed over an unmoving and immiscible stationary phase.  The mobile phase is comprised of the sample and a carrier gas (typically helium, nitrogen, argon, hydrogen or air).  The purity of the carrier is critical and ultra-pure gases are normally purchased or, in the case of air, zero air can be generated on site for cost savings and high purity.   

GC separation resized 600

The time in which it takes components in the carrier to pass through the stationary phase, known as the retention time (tR), is determined.  The more soluble a component is in the stationary phase, the higher the retention time. 

Once a component passes through the stationary phase, a detector allows the user to identify each of them, determine their mass and quantify the concentration.  There are a wide variety of detectors, and the detector chosen depends on the components and the needs of the user. 

The most commonly used detectors are the flame ionization detector (FID) and the thermal conductivity detector (TCD). They share a common sensitivity and functional concentration range.  TCDs can be used to detect virtually any component other than the carrier gas and is non-destructive, while FIDs are sensitive primarily to hydrocarbons and incinerate the entire sample.

Most importantly, proper calibration of the GC is essential.  By calibrating GC, the various retention times for compounds of interest are detected. Also, the area under the peak can be used to determine the concentration of the sample components by comparison to a determined calibration curve. 

GC response time resized 600A calibration curve is generated by running various dilutions of the compound/s of interest and then plotting response time and against concentration.  These points represent the calibration curve. No two compounds will produce exactly the same calibration curve, and the user must construct a calibration curve for each analyte.  It is also best practice to rerun the calibration at frequent intervals.  Precise calibration standards can be generated by gas dilution systems, which offer the advantage of on-site gas blending of 100% pure gases cylinders, providing a solution to using numerous, costly premixed cylinders of gas.  

Interested in learning more?  Subscribed to the Post or Contact Us!  We look forward to hearing from you.

Throwback to 1988

 

Just for fun, here is a look at an ad from 1988, when Environics was just 2 years old.  It features our discontinued Series 200, which was replaced by our Series 2000 and Series 4000 gas mixers.

series 200 ad 1988 resized 600

Boston Strong!

 

We are celebrating not only Halloween today, but our Champion Red Sox!  Congratulations from all of us to the #Boston #RedSox for winning the 2013 World Series. GO SOX!

 

Customer Focus - Working with High Concentrations of Explosive Gases

 

Often, customers come to us looking for a gas flow management system to fit a very particular set of criteria.  In some cases, this requires just minor customization of a current Environics model.  In other cases, a completely unique design is required.  Today, I share with you one interesting example.  Although I focus on the first system we designed, we have since made similar systems for other customers whose needs parallel these.

explosive gas mixer

Our customer needed to dilute explosive gases at high concentrations in order to calibrate gas detectors.  After working with our sales and engineering teams, we designed and built a modified version of our Series 4040 gas dilution system which included a dual chassis design.

The electronics enclosure includes the power supply and PC boards for controlling the Mass Flow Controllers (MFC) and direct acting solenoid valves in the second enclosure. The electronics enclosure connects to a computer via a 9 pin serial port connector and cable. The 4040 software, on the computer, communicates with the microcomputer board inside the electronics enclosure.

continuous purge gas mixer
The second enclosure is sealed and houses the MFCs, valves and components to support the enclosure purge. A continuous purge flows through the enclosure while it is running. This serves two purposes. The first is to carry out heat built up by the internal components. The second is to dilute any potential leaks that may develop. The gas plumbing inside this enclosure was vacuum leak tested to 1X10-8 ATM CC/SEC He.

In addition to continuous purge flow, the enclosure is pressurized to approximately 5” H20 while running the enclosure purge. This provides and indicator that the purge is activated as well as preventing any air leaks into the enclosure from outside. A safety vent was  added to vent the enclosure to atmosphere if the pressure inside the enclosure reaches 20” H20. This could happen if for some reason the purge vent becomes blocked or the pressure on the purge rotameter is too high.

The two enclosures are connected electrically via two control cables labeled MFCs and VALVES. An earth ground wire is connected from the electronics chassis to the aluminum mounting plate inside the purged enclosure. This safely discharges any static electricity that can build up in a system with flow.

Have a similar need?  You can contact us at (860) 872-1111 or here for more information.

 

 

News - EPA releases a series of PSAs on Climate Change

 

The Environmental Protection Agency of the United States (US EPA) recently released a series of 30 sec US EPA ambient and 1 minute public service videos on climate change. The videos discuss small changes people can make to their daily lives that have an impact on emissions. Citizens are encouraged to reduce the amount of energy they use to both cut their own utility costs and protect their health.  The cumultive effect of these small changes to the economy and environment are stressed. The series was developed in support of President Obama's Climate Action Plan, released in June.  In his plan, the President stressed the importance of reducing carbon pollution while simultaneously prepareing for the impacts of changes to the climate.

What do you think?  Do you give thought to how your actions may impact the climate?  What things do you do at work and home to minimize your carbon "footprint."

You can watch the videos here: http://www.youtube.com/playlist?list=PLBhfkkujnoRAgTFtLreccWDfpxBIspCGv

Customer Focus - Use of Hypoxia to Detect Deficits After Concussion

 

From time to time, we like to showcase the research of our customers.  Our team is always interested in learning more about the huge variety of research projects and discoveries made in labs using Environics systems.

The Environics Reduced Oxygen Breathing device is used worldwide in the training of aviators and others who regularly are flying at altitude.  Using the ROBD2, they learn what it feels like to be hypoxic.  However, the system is not solely used for training.  Several researchers have used the ROBD2 for hypoxia related projects.  Today, we focus on the results of a recently published study by lead author, Leonard Temme (Vision Sciences Branch, Sensory Research Division, U.S. Army Aeromedical Research Laboratory at Fort Rucker, AL).

ROBD2

Mild traumatic brain injury (mTRI) is more commonly known as concussion.  In general, it is suggested the recovery from this type of injury takes 7-10 days, although there is more and more research in terms of those who suffer mTRI repeatedly (such as football players).  This recovery time is based on observations made in individuals under unstressed environmental conditions such as a doctor’s office or hospital. The authors wanted to examine how putting someone under stress would affect people who have a history of such a trauma.  The question was would a person with a medical history of a concussion who seems recovered become symptomatic when exposed to a stress such as sleep deprivation, pharmaceuticals, extreme temperature, anxiety or hypoxia.

A chance observation made during a training study led the authors to this question.  Pilots were exposed to a normobaric hypoxic condition that simulated conditions seen at 18,000 feet using an ROBD2. While “flying” pilot hypoxia trainingunder standard conditions, the pilots behaved comparably.  However, when the pilots were breathing air with only ~10% oxygen, one pilot lost control of the aircraft without realizing it. Looking into this pilot’s medical history, the researchers found he had experienced a significant concussion ejecting from a high-performance aircraft.  This chance observation led the authors to this question:  Would a stressor, in this case hypoxia, help uncover a symptom that was unobservable under normal conditions? 

To begin, two sets of 36 subjects between 18-50 were gathered from the community:  one group with a history of mTBI and one without.  The subjects were then matched “on the basis of age, gender, tobacco smoking consumption, weight, height, and body mass index” for comparison purposes.  Utilizing eight tests from the BrainCheckers test battery, the subjects were examined under both standard conditions and three different reduced oxygen conditions. 

While seven of the tests showed no significant difference between groups, the performance on the M2S test, which is a measure of short-term visual memory, did.  Under reduced oxygen stress, those with a history of mTBI showed a significant impairment when compared with the control group. 

The researchers’ findings open up potential avenues for using hypoxia to test brain stress following mTBI.   The authors’ state, “Such a capability would be particularly important since mTBI, even when apparently completely recovered using conventional examination strategies, may include deficits observable only under stress.”

Having a way to clinically measure recovery from mTBI would be a great advantage.  It will be interesting to follow these studies. 

To read the full article, click here.

Have an interesting project using your Environics system?  Share it with us and you may be the included in our next focus!

News: Revisions to the US EPA Air Emissions Reporting Rule

 

On June 30, 2013, the US Environmental Protection Agency released a revision to the Air Emissions Reporting Rule (AERR). The rule states the goal of the revisions is to "reduce reporting burden for state, local and tribal agencies, improve consistency and clarity with other rules, and better reflect current inventory technologies and practices."

The AERR was first published in 2008 as a replacement to the previous Consolidated Emissions Reporting Rule (CERR), which was published in 2002.  Both regulations were created to improve the ability of the EPA to gather emissions data on a national level.  The data is used to create a national inventory of air pollutant emissions. You can see this data in use and search for the conditions in your area at the EPA's MY Environment.

air quality ambient monitor

The improved AERR aims to grant states more flexibility on how to collect and report this emissions data.  These increased permissions give the state programs the ability to operate more efficiently.  To find out more visit the EPA's AERR page.

News : Reduced Oxygen Breathing Device in Naval Pilot Training

 

Last week, in the YouTube program "Scrubbing In" presented by Navy Medicine, focused on training Naval and Marines for the feeling of hypoxia.  In this week's show, the hosts are at Navy Medicine Aviation Survival Training Center in Patuxent River, Md, and the training application of the Environics Reduced Oxygen Breathing Device (ROBD2) is featured. 

ROBD2 training deviceLCDR Corey Littel, the Director of the Aviation Survival Training Center, discusses what hypoxia is and how the pilots are trained.  The Leutenant Commander discusses the use of hypobaric chambers for hypoxia awarenewss training.  He explains this method is "slightly outdated."  We then are shown training lab containing a number of ROBD2 systems, as well as the use of the "much more modern means of delivering a mask on version" of hypoxia training.

 

 Produced by U.S. Navy Bureau of Medicine and Surgery Visual Information Directorate, published April 10, 2013

News : Ambient Air Quality in China

 

A recent article on the quality of the air in China began with this frighening statistic: Outdoor air pollution contributed to 1.2 million premature deaths in China in 2010, nearly 40 percent of the global total.  Brought into the headlines during the Beijing Olympics, the poor quality of the air in China is nothing new.  

beijinghttp://en.wikipedia.org/wiki/File:Beijing_smog_comparison_August_2005.png

In February 2012, the China State Council passed ambient air quality standards, GB 3095-2012.  The goal of these improved standards is to improve both the environment and the health of those living there.   with the aim of improving the living environment and protecting human health. For the first time, particulates with a diameter of 2.5 microns or less, also known as PM2.5, is included in the standards.  PM2.5 are the smallest particulate matter and penetrate the body’s tissues most deeply.  Once inhaled, the particles may cause respiratory infections and are especially dangerous for children and the elderly, as well as those with existing respiratoy issues.  Ozone levels are also set in the standard with the new 8 hour ozone standards matching the interim targets set by the World Health Organization (WHO).

China AQ Standards Compare resized 600http://cleanairinitiative.org/

For years, Chinese officials had been collecting the data but failed to release it publically.  The US embassy in Beijing posts automated air quality measurements on an hourly basis at @beijingair.  Last June, there was debate over the accuracy of the readings due to large disparagies between the readings by Chinese officials and the embassy.  Chinese authorities asked that they and other stop publishing, what they described as "inaccurate and unlawful" data.

By early this year, many news reports emerged that the air quality in Beijing has reached hazard ous levels.  With 100 being the maximum "safe" level and 300 being a level at which those at risk should remain indoors, reports in Beijing ranged from 400-800 micrograms.

The timeline for implementing the new standards is January 2016.  Some cities may be required to implement the changes ahead of this date, as determined by Ministry of Environmental Protection.  Overall, provinces are being encouraged to implement the new standards as soon as they are ready.

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