Monthly Archives: July 2011

Here is a cool bit of news this morning; Boeing is working with Embraer and the Inter-American Development Bank to study the production of renewable jet fuel made from Brazilian sugarcane. Even sweeter is that this jet fuel is produced by one of our customers, Amyris! According to Amyris CEO John Melo the goal here is to, “help us replace fossil fuels with a renewable jet fuel that surpasses both technical and sustainability criteria.”

The study is being directed by ICONE, a non-profit Brazilian research organization, and the World Wildlife Fund is acting as an independent reviewer and advisor. Sounds like it's a dedicated coalition of minds working on this issue. We’re thrilled that we can indirectly support this kind of innovation and will look forward to seeing the results in early 2012.

You can learn more about this announcement by reading the original press release here.

Do you feel like sample prep is taking up all your time? If you answered yes then you aren’t alone according to this recent survey from Lab Manager Magazine. The results of 245 lab professionals show that in chromatography about 80% of their time is spent on the process of sample preparation – from collection to data management.

This survey found that filtration is the most common technique used to achieve sample preparation, with Solid Phase Extraction also ranking as a common method. Add these results together and it looks like quite a few of you are spending a lot of time with our products. So the question becomes, how can you improve your sample preparation process? When asked this question, 97% of respondents said they would look to lower costs, such as by using less solvent or using cheaper materials.

One area we can assist in is providing a number of cost-efficient syringe filters for HPLC solutions. Low cost Cellulose Acetate and Polyethersulfone filters are available in an assortment of pack sizes for any budget, and our discounts on expired or soon to expire sterile syringe filters are a great value.

Have you mastered the art of HPLC sample prep? What other activities are eating up your time? Click on the title to share your tips in the comments!

The Silt Density Index is most frequently used to determine fouling potential prior to RO filtration. You can think of SDI as a bouncer, keeping the riff-raff out of the RO feed water. The higher the number, the greater the likelihood of fouling. The maximum SDI number allowed depends on the type of RO membrane being used; most manufacturers recommend a maximum SDI of 4 or 5.

SDI is found by calculating the rate at which a membrane filter is plugged. ASTM standard D4189-07 defines that the nominal filter for this application is a white hydrophilic MCE membrane filter, with 0.45 μm pore size and a 47 mm diameter. The reason this particular membrane is used is that it is more susceptible to plugging from colloidal material than from hard particles such as sand, therefore giving a better indication of the factors that might plug an RO membrane down the line.

Other measures that can be derived from the SDI include the plugging factor and the Modified Fouling Index (MFI). The plugging factor expresses the level of suspended solids as a percentage of the measured SDI value to the maximum SDI value, so a 100% plugging factor would indicate that your membrane is completely plugged. The MFI incorporates cake filtration theory into its calculation of fouling potential. Since this formula is more complex than SDI, it is not as frequently used in the field.

SDI can be determined manually or automatically with a measurement kit. Got any tips or experiences measuring SDI? Let us know in the comments!

Of all the membrane disc filter accessories that we carry, the static eliminator probably gets the most technical questions. Whereas items like the cytoclear glass slides and stainless steel membrane filter tweezers are very straightforward in their purpose and operation, how a static eliminator works may not be as intuitive.

Static eliminators are used on Polycarbonate or Polyester membranes when they are going to be subject to precise analytical balance measurements that could be affected by the presence of static or dust particles on the filter. Static eliminators can perform this function in a few different ways, such as by using alternating current or by using small amounts of a radioactive element to remove electrons. The static eliminators that we carry use a naturally occurring radioactive element called Polonium-210 (It was discovered by Marie and Pierre Curie and named after Marie Curie’s homeland of Poland) in order to function.

This type of static eliminator is referred to as an alpha ionizer since it emits alpha particles (Helium in this case) which create an intrinsically balanced output of positive and negative ions to remove the static charge. The reason our static eliminators utilize this method is because alpha ionizers don’t require an electrical power supply, which is more convenient and safer for volatile environments.

Now even though we mentioned that our static eliminators contain this radioactive material (and that said material was discovered by Marie Curie), this item poses no health risk, as the alpha particles will not pass through the skin and the element is sealed. According to the International Atomic Energy Agency, “Po-210 [Polonium-210] is not a concern and Po-210 does not represent a risk to human health as long as Po-210 remains outside the body.” Since the alpha particles can only travel a few centimeters and they are easily blocked by the skin or even a sheet of paper, safety concerns are minimal. Furthermore, the static eliminators we carry are manufactured and distributed in accordance with the provisions provided by the U.S. Nuclear Regulatory Commission, so you can use them without worry!

As we’ve brought up before, the Google Science Fair has turned out some amazing projects from 13-18 year-olds all over the world, and today Google announced the very deserving winners from each age group. Taking home the top prize is Shree Bose of Fort Worth, Texas whose project seeks to improve the effectiveness of chemotherapy treatment for ovarian cancer (you know, typical kids’ stuff). The techniques she uses, such as flow cytometry, microscopy and western blotting, will no doubt be familiar to many of our visitors.

Other winning projects covered the effects of environmental pollutants on asthma patients and methods for reducing carcinogens in our food. That all three of these winners were girls is an added bonus that will hopefully dispel some poorly conceived stereotypes about women in science.

All in all, there were some mind-bendingly impressive projects and the participants can look forward to bright futures as innovators in their chosen fields.

We updated our site search feature this week to include product descriptions in the search results! Now you can quickly find and compare item specifications right from the search results. Just another effort to make your lives a little bit easier…

This study from the ACS journal Applied Materials & Interfaces has been making headlines recently for introducing a new way to purify drinking water. Scientists from Rice University have created a new filter material, dubbed “super sand,” by coating regular sand with the nanomaterial graphite oxide. Their tests have shown that this super sand has the potential to be a cheap form of water filtration for developing areas.

The use of sand as a water filter isn’t anything new – it’s actually been done for around 6,000 years. However, by combining this old world technique with cutting edge nanotechnology scientists have made sand filtration at least 5 times more efficient. Their report indicates that the modified sand adsorbed 6 times the amount of liquid mercury and 5 times as much heavy metal and organic dye than regular sand.

In addition to the improved filtration capacity, there are other benefits of super sand that increase its prospects for real-world integration. The materials needed to make super sand, graphite and regular sand, are inexpensive and readily available. Another crucial advantage is that super sand can be created around room temperatures. These factors lead experts to believe that super sand could become a cost-efficient and viable method of water filtration in the future.

As you can see, the Sterlitech blog that we started last year has now been moved over to be a part of our main site. If this is your first visit, our blog is where you can find information on new and unique applications, answers to your inquiries, miscellaneous product info, company announcements, and the occasional piece of odd news from the vast universe of science.

For returning visitors, we've brought over the archives from the old blog. If something you're looking for has been lost or broken in the transition, please let us know so we can fix it right away.

You can use the blog search tool on the left to reference the previous posts, or select a category to browse a particular topic. The blog search tool is for the blog only, so to search content on our main site you'll want to continue to use the search bar on the top of the page. We welcome (non-offensive, please) comments so feel free to leave them on any of our posts to tell us all what you think.

And now that we got that out of the way, we hope you enjoy!