Project Updates

How does the Scott Test for cocaine work?

Author: Marya Lieberman

The Scott test has been used for over 50 years as a presumptive test for cocaine.   It involves a series of reagent additions and color changes...and if it's not done and interpreted correctly, it can send innocent people to jail.  This crystal structure now published in Acta Cryst E gives insight into what's going on in the test.  

Bis(N,N-diethyl-4-methyl-4-piperazine-1-carboxamide) tetra­kis­(iso­thio­cyanato-κN)­cobalt(II), a model compound for the blue color developed in the Scott test. Oliver, A. G., Lockwood, T.-L. E., Zinna, J. & Lieberman, M. (2023). Acta Cryst. E79, 163-166

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Turkey Run 2022

Author: Marya Lieberman

2022 Group At Turkey Run Analytical Conference Heather And Kat Organizers
The Lieberman group takes a moment to relax at Turkey Run

Turkey Run Analytical Conference 2022 was held at Turkey Run State Park in Indiana, and attracted researchers from Indiana, Ohio, and Illinois. In addition to Heather, Kat, Alyssa, Rachel, and Ornella, undergraduates Devena and Sarah presented posters, and Yukun from the Peaslee group also gave a poster. Congratulations to Heather Whitehead and Kathleen Hayes for organizing a great scientific meeting!  …

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Congratulations to Olatunde Awosiji Awotunde, Nicholas Roseboom, and Jin Cai!

Author: Marya Lieberman

Discrimination of Substandard and Falsified Formulations from Genuine Pharmaceuticals Using NIR Spectra and Machine Learning

Near-infrared (NIR) spectroscopy is a low-cost analytical tool for rapid characterization of pharmaceuticals. Usually, it's necessary to build up a "library" of NIR spectra from authentic products in order to identify real and fake formulations.  In this paper, we developed a simple training method that uses binary mixtures of a pharmaceutical (acetaminophen) with two different cutting agents, and used several different data analysis models to extrapolate the training samples to real and fake samples of popular brands of acetaminophen tablets.   While none of the models was able to correctly classify all the samples, a simple voting algorithm was able to compensate for the weaknesses of the models and classify 93% of the samples correctly.  …

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Congratulations to Heather Whitehead, whose paper on instrument-free detection of DNA with Nile Blue was just accepted by Analytical Methods!

Author: Marya Lieberman

Many nucleic acid tests (NATs) rely on a DNA amplification step as the detection mechanism for pathogens, viral load, and so on.  Usually, DNA concentration is measured using a spectrophotometric instrument that costs tens of thousands of dollars.  In this paper, Heather Whitehead used an inexpensive dye that binds to DNA and a cell phone to measure the concentration of double stranded DNA in the same concentration range commonly used to analyze NAT results. The color of Nile Blue dye shifts from blue to blue-purple to blue  as it binds to DNA.  While it's been known for many years that Nile Blue dye changes color when it binds to DNA, and that property has been used to develop instrumental assays, Heather figured out that by using different concentrations of the Nile Blue dye and monitoring the red, green, and blue channel intensities, the concentration of double stranded DNA can be measured with an error of less than 10 ug/ml.  …

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Health systems model shows cost-effectiveness of screening amoxicillin quality

Author: Marya Lieberman

Sarah Bliese's paper with the Ozawa group at NC State is now published!  Sachiko Ozawa's group developed an agent-based model, ESTEEM (Examining Screening Technologies with Economic Evaluations for Medicines), to estimate the effectiveness and cost savings of incorporating PADs and aPADs in amoxicillin quality surveillance in Kenya. We compared the current testing scenario (batches of entire samples tested by HPLC) with an expedited HPLC scenario (testing smaller batches at a time), as well as a screening scenario using PADs/aPADs to identify poor-quality amoxicillin followed by confirmatory analysis with HPLC. The PADs/aPADs screening scenario identified and removed poor-quality antibiotics faster than the expedited or regular HPLC scenarios, and reduced costs significantly. The model estimates that use of early screening tests could avert 360-870 pneumonia deaths per year in children under age 5 while reducing the number of HPLC tests required. …

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Oopsy!

Author: Marya Lieberman

A US pharmaceutical company just announced a recall of two lots of drugs which were "inadvertently mixed up" by the manufacturer.…

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