We live in a polarized world. No, we aren't talking about politics -- we're talking about light. Much of the light we see and use is partially polarized, meaning its electric field vibrates in specific directions. Lenses designed to work across a range of applications, from phone cameras to ... more
Separating Drugs with MagLev
Magneto-Archimedes levitation for identification of illicit drugs in powdered mixtures
The composition of suspicious powders that may contain illicit drugs can be analyzed using a quick and simple method called magneto-Archimedes levitation (MagLev), according to a new study published in the journal Angewandte Chemie. A team of scientists at Harvard University, USA, has developed the MagLev method to differentiate common street drugs in dilute mixtures. The method could complement or even replace other portable drug identification techniques, the scientists suggest.
Synthetic opioids—mainly fentanyl and its analogues—are a group of substances that were involved in 30,000 overdose-related fatalities in 2017 in the US alone. Law enforcement officers have to assess the contents of small samples of powders quickly and precisely, and cases of fentanyl detection are increasing in frequency. Sniffer dogs or colorimetric assays are relied on, which allow a rough but only qualitative analysis. However, an innovative, more complete analysis method has now been developed by the group of George M. Whitesides at Harvard University, in collaboration with colleagues from the Drug Enforcement Administration (DEA), Dulles, USA. Using MagLev, the scientists could easily separate and even isolate different drugs (as powders) from sample mixtures.
The MagLev device consists of two strong permanent magnets that flank a cuvette filled with a solution of a paramagnetic gadolinium chelate complex. When the scientists add a mixture of powdered drugs to the cuvette, the different substances in the mixture levitate; the powders wander and equilibrate at different heights in the cuvette that correspond to their characteristic density. Thus, the once homogeneous powder is divided into several levitating clouds, each one containing a relatively pure substance. The authors say they could separate up to seven test substances simultaneously. Among the substances that have been separated were prominent illicit drugs and adulterants found in mixtures, such as fentanyl, cocaine, heroin, lidocaine, caffeine, and methamphetamine.
For substance identification, the operator of the MagLev device compares the observed density of an unknown fraction with known densities of illicit drugs. However, the scientists also suggest that MagLev can be used as a preparative technique that separates and concentrates dilute substances, such as fentanyl, which might be present in a fraction of less than five percent by weight. In this case, the operator pipettes the fractionated components out of the cuvette, washes them with solvent, and dries them. Fractionation, and thus, concentration makes it easier to identify dilute drugs in mixtures using more selective but less sensitive techniques, such as FTIR or Raman spectroscopy, according to the authors.
Limitations of the technique are that the samples need to be separated as solid powders and should not dissolve in the paramagnetic solution, which contains gadolinium chelate complex and the nonpolar solvents hexane and tetrachloroethylene.
The authors of the study eventually hope to make the MagLev device commercially available to law-enforcement officers.
- drug analysis
- magnetic levitation
Today's optical systems -- from smartphone cameras to cutting-edge microscopes -- use technology that hasn't changed much since the mid-1700s. Compound lenses, invented around 1730, correct the chromatic aberrations that cause lenses to focus different wavelengths of light in different spot ... more
All humans begin life as a single cell that divides repeatedly to form two, then four, then eight cells, all the way up to the ~26 billion cells that make up a newborn. Tracing how and when those 26 billion cells arise from one zygote is the grand challenge of developmental biology, a field ... more
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences have made the world’s smallest radio receiver – built out of an assembly of atomic-scale defects in pink diamonds. This tiny radio — whose building blocks are the size of two atoms — can withstand extrem ... more
The folding state of the proteins in live cells often reflect the cell’s general health. Australian scientists have developed a molecular probe that senses the state of the proteome—the entire set of the proteins—by measuring the polarity of the protein environment. The fluorescence signal ... more
Nanoclusters are little “heaps” of a few atoms that often have interesting optical properties and could become useful probes for imaging processes in areas such as biomedicine and diagnostics. In the journal Angewandte Chemie, researchers have introduced a nanocluster of 16 silver atoms sta ... more
Many industrial and agriculture processes use chemicals that can be harmful for workers and the ecosystems where they accumulate. Researchers from Thailand have now developed a bioinspired method to detect and detoxify these chemicals in only one step. As they report in the journal Angewand ... more
- 1analytica 2020: New instruments for battery research
- 2Ultrafast birth of free radicals observed in water
- 3Looking at the good vibes of molecules: a new method for label-free metabolic imaging
- 4Eppendorf with new CEO dual leadership
- 5A fine sense for molecules
- 6Complete filling of batches of nanopipettes
- 7Sensing Protein Wellbeing
- 8Researchers create nanoscale sensors to better see how high pressure affects materials
- 9Watching complex molecules at work
- 102D materials: arrangement of atoms measured in silicene