New method to measure insecticide on mosquito netting

Recently scientists at NC State’s Analytical Instrumentation Facility, working with researchers at the Centers for Disease Control and Prevention, published new methods to measure the amount of insecticide on mosquito netting. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), the team studied various samples of mosquito netting to determine the amount of insecticide necessary for the netting to be effective in killing mosquitoes. To learn more, visit the NC State press release or the online journal article.

“Imaging and Quantitative Analysis of Insecticide in Mosquito Net Fibers Using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS)”

Stephen C. Smith, Centers for Disease Control and Prevention; Chuanzhen Zhou, Fred A. Stevie, and Roberto Garcia, North Carolina State University

Abstract: Time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis was used to qualitatively and quantitatively assess the distribution of permethrin insecticide on the surfaces and interiors of Olyset® long-lasting insecticidal net (LLIN) fibers. Total insecticide content in LLINs has been established using many analytical methods. However, it is important to quantify the bioavailable portion residing on the fiber surfaces for incorporated LLINs. ToF-SIMS is a very surface sensitive technique and can directly image the spatial distribution of permethrin insecticide on the surface of Olyset fibers. Surface permethrin appeared as patchy deposits which were easily removed by acetone and reappeared after several days as interior permethrin migrated (bloomed) from the fiber interior. After a wash/incubation cycle, permethrin deposits were more diffuse and less concentrated than those on the as-received fibers. ToF-SIMS is particularly sensitive to detect the Cl- ion, which is the characteristic ion of permethrin. Ion implantation and quantification of dopants using SIMS is well established in the semiconductor industry. In this study, quantitative depth profiling was carried out using 35Cl ion implantation to correlate secondary ion yield with permethrin concentration, yielding a limit of detection of 0.051 wt% for permethrin. In some cases, surface concentration differed greatly from the fiber interior (>1 µm below the surface). Two- and three-dimensional mapping of Cl at sub-micrometer resolution showed permethrin to be dissolved throughout the fiber, with about 2 vol% residing in disperse, high-concentration domains. This suggests that these fibers fall into the class of monolithic sustained-release devices. It is expected that ToF-SIMS can be a valuable tool to provide insight into the insecticide release behavior of other LLIN products, both current and future.

AIF now home to compact microCT system

The Analytical Instrumentation Facility (AIF) is now home to a Bruker SkyScan 1174 microCT system. This compact microCT can be used to image a variety of samples in three-dimensions with down to 10 micron spatial resolution. A suite of software tools is  included with the system for complex image reconstruction, processing, and analysis. Several example images can be found here, and the specs are listed below. The instrument will be available for both research and outreach activities by early October. For more information on training and access, please contact Maude Cuchiara.

X-ray source 20-50kV, 40W maximum power, filter holder for energy selection
X-ray detector 1.3Mp CCD coupled to scintillator by lens with 1:6 zoom range
Spatial Resolution 6…30 µm pixel size, approximately 10 µm low-contract resolution
Object Size 5 – 30mm in diameter, 50mm in length (50mm vertical travel)
Radiation safety <1 µSv/h at 10cm from the instrument surface

 

AIF Seeking Qualified Business Services Coordinator

The Analytical Instrumentation Facility (AIF) at NC State seeks a talented individual to join our team as a Business Services Coordinator. The Business Services Coordinator oversees the business and financial management of a complex and evolving Service Center within the College of Engineering. This individual performs a range of responsibilities in areas including Business Administration, Financial Management, Information Analysis and Decision Making, Communication, and Human Resources. Most notably, the individual analyzes and evaluates facility operations and data and is empowered to make decisions to increase efficiency. The individual also manages one Administrative Support Specialist position in the unit. More details are available in the job description posted on the website: http://jobs.ncsu.edu/postings/76885

The AIF is NC State’s primary shared facility for materials characterization with a mission to enable and lead state-of-the-art research through acquisition, development, maintenance, training, and access to major analytical and materials characterization instrumentation. Through the support of engaged faculty and experienced staff, the AIF supports state-of-the-art scanning and transmission electron microscopes, X-ray scattering and spectroscopy instruments, mass spectrometry, scanning probe microscopy, nanoindentation, and extensive sample preparation facilities.

Questions about the position can be directed to aif-contact@ncsu.edu.

AIF Seeks Applications for Talented Electron Microscopist

The Analytical Instrumentation Facility (AIF) seeks a talented and industrious experimentalist to join our team as an Electron Microscopy Specialist. The AIF is NC State’s primary shared facility for materials characterization with a mission to enable and lead state-of-the-art research through acquisition, development, maintenance, training, and access to major analytical and materials characterization instrumentation. Through the support of engaged faculty and experienced staff, the AIF supports state-of-the-art scanning and transmission electron microscopes, X-ray scattering and spectroscopy instruments, mass spectrometry, scanning probe microscopy, nanoindentation, and extensive sample preparation facilities. The AIF is a core nanotechnology user facility in the new Research Triangle Nanotechnology Network (RTNN), a site in the National Nanotechnology Coordinated Infrastructure (NNCI).

Primary responsibilities of the new position include training new users (both internal users from NC State and those external to NC State) as well as performing service work for external clients. The ideal candidate will be customer-focused and exhibit a commitment to excellence in all technical and organizational aspects of their role. The new Postdoc will work closely with the AIF and RTNN teams in serving the needs of university, industrial, and government researchers from across NC State, the North Carolina Research Triangle, and the nation.

Please encourage talented applicants to apply:
Full-time staff position: https://jobs.ncsu.edu/postings/76529
Postdoc: https://jobs.ncsu.edu/postings/76522

Upcoming seminar: “Materials Science in Caribbean Art and Archaeology”

We are excited to announce an upcoming seminar by Professor Antonio Martínez-Collazo. Professor Martínez will discuss his work using materials characterization techniques to study works of art and archaeological artifacts. Following the talk, the Analytical Instrumentation Facility (AIF) at NC State will host tours for interested attendees to learn more about available characterization techniques and instrumentation.

More information can be found on the event website.