Posts Tagged ‘chemistry’

cientific studies on the cleaning power of spit, a lone fruit fly’s ability to spoil wine, and cannibals’ caloric intake garnered top honors at the 28th Ig Nobel Prize ceremony. The seriously silly citations, which “honor achievements that first make people laugh, and then think,” were awarded on Sept. 13 at Harvard University’s Sanders Theatre. Entertaining emcee Marc Abrahams and the savvy satirists of the Annals of Improbable Research produced the ceremony.

The coveted Chemistry Prize went to Portuguese researchers who quantified the cleaning power of human saliva. Nearly 30 years ago, conservators Paula Romão and Adília Alarcão teamed up with late University of Lisbon chemist César Viana to find out why conservators preferred their own saliva to any other solvent for cleaning certain objects—with the goal of finding a more hygienic substitute. Compared with popular solvents, saliva was the superior cleaning agent, particularly for gilded surfaces. The researchers attributed the polishing power to the enzyme α-amylase and suggested solutions of this hydrolase might achieve a spit shine similar to spit (Stud. Conserv. 1990, DOI: 10.1179/sic.1990.35.3.153).

A fruit fly in a glass of wine is always an unwelcome guest. But it turns out that as little as 1 ng of Drosophila melanogaster’s pheromone (Z)-4-undecenal can spoil a glass of pinot blanc. That discovery, from researchers led by Swedish University of Agricultural Sciences’ Peter Witzgall, received the Ig Nobel’s Biology Prize. Only female fruit flies carry the pheromone, so males can swim in spirits without delivering the offending flavor, but the Newscripts gang still prefers to drink wine without flies (J. Chem. Ecol. 2018, DOI: 10.1007/s10886-018-0950-4).

Putting the paleo diet in a new perspective, University of Brighton archaeologist James Cole took home the Nutrition Prize for calculating that Paleolithic people consumed fewer calories from a human-cannibalism diet than from a traditional meat diet. Thus, Cole concludes, Paleolithic cannibals may have dined on their companions for reasons unrelated to their nutritional needs (Sci. Rep. 2017, DOI: 10.1038/srep44707).

A team led by Wilfrid Laurier University psychologist Lindie H. Liang won the Economics Prize “for investigating whether it is effective for employees to use voodoo dolls to retaliate against abusive bosses.” Push in some pins: The findings indicate voodoo doll retaliations make employees feel better (Leadership Q. 2018, DOI: 10.1016/j.leaqua.2018.01.004).

The Newscripts gang previously reported about this year’s winners of the Ig Nobel for medicine, physicians Marc Mitchell and David Wartinger, who found that riding roller coasters can help people pass kidney stones (J. Am. Osteopath. Assoc.2016, DOI: 10.7556/jaoa.2016.128).

The Reproductive Medicine Prize went to urologists John Barry, Bruce Blank, and Michel Boileau, who, in 1980, used postage stamps t
o test nocturnal erections, described in their study “Nocturnal Penile Tumescence Monitoring with Stamps” (Urol. 1980, DOI: 10.1016/0090-4295(80)90414-8).

The Ig Nobel committee also gave out a Medical Education Prize this year, to gastroenterologist Akira Horiuchi for the report “Colonoscopy in the Sitting Position: Lessons Learned from Self-Colonoscopy” (Gastrointest. Endoscopy 2006, DOI: 10.1016/j.gie.2005.10.014).

Lund University cognitive scientists Gabriela-Alina Sauciuc and coworkers claimed the Anthropology Prize “for collecting evidence, in a zoo, that chimpanzees imitate humans about as often, and about as well, as humans imitate chimpanzees” (Primates 2017, DOI: 10.1007/s10329-017-0624-9).

For a landmark paper documenting that most people don’t read the instruction manual when using complicated products, a Queensland University of Technology team led by Alethea L. Blackler garnered the Literature Prize (Interact. Comp. 2014, DOI: 10.1093/iwc/iwu023).

And finally, the Ig Nobel Peace Prize was awarded to a team from the University of Valencia’s University Research Institute on Traffic & Road Safety “for measuring the frequency, motivation, and effects of shouting and cursing while driving an automobile” (J. Sociol. Anthropol. 2016, DOI: 10.12691/jsa-1-1-1).

The Ig Nobel ceremony can be viewed in its entirety at, and National Public Radio’s “Science Friday” will air an edited recording of the ceremony on the day after U.S. Thanksgiving.


Ever wish you could do a quick “breath check” before an important meeting or a big date? Now researchers, reporting in ACS’ journal Analytical Chemistry, have developed a sensor that detects tiny amounts of hydrogen sulfide gas, the compound responsible for bad breath, in human exhalations.

According to the American Dental Association, half of all adults have suffered from bad breath, or halitosis, at some point in their lives. Although in most cases bad breath is simply an annoyance, it can sometimes be a symptom of more serious medical and dental problems. However, many people aren’t aware that their breath is smelly unless somebody tells them, and doctors don’t have a convenient, objective test for diagnosing halitosis. Existing hydrogen sulfide sensors require a power source or precise calibration, or they show low sensitivity or a slow response. Il-Doo Kim and coworkers wanted to develop a sensitive, portable detector for halitosis that doctors could use to quickly and inexpensively diagnose the condition.

To develop their sensor, the team made use of lead(II) acetate – a chemical that turns brown when exposed to hydrogen sulfide gas. On its own, the chemical is not sensitive enough to detect trace amounts (2 ppm or less) of hydrogen sulfide in human breath. So the researchers anchored lead acetate to a 3D nanofiber web, providing numerous sites for lead acetate and hydrogen sulfide gas to react. By monitoring a color change from white to brown on the sensor surface, the researchers could detect as little as 400 ppb hydrogen sulfide with the naked eye in only 1 minute. In addition, the color-changing sensor detected traces of hydrogen sulfide added to breath samples from 10 healthy volunteers.

By Nala Rogers

Even drugs that clear the body quickly leave traces about when and where they were used. In fact, many traces get flushed down the toilet — and those traces can be surprisingly revealing.

In a study published last month in the journal Science of the Total Environment, researchers analyzed sewage from two towns in western Kentucky. By testing for active ingredients and metabolites of marijuana, cocaine, amphetamine, methamphetamine, ecstasy and several opioids, they were able to estimate the average quantity of each drug consumed per 1,000 people in the population on any given day. This allowed them to infer how drug use changed during special events in the summer of 2017.

In both communities, significantly higher levels of amphetamine, methamphetamine, cocaine, morphine and methadone were found in the wastewater on July 4 than on a typical day. In particular, methamphetamine levels were high on Independence Day, with levels doubling in one town and rising by half in the other.

One of the towns was in the path of the total solar eclipse that crossed the country August 21. In that town, the eclipse brought a significant uptick in amphetamine, methamphetamine, cocaine, morphine and marijuana. The measurements suggested that 1,450 milligrams of amphetamine per 1,000 people was consumed on the day of the eclipse — enough to get about 2.9 percent of the town’s population high. That represented a roughly 60 percent increase over the amphetamine residues found on a typical day.

Of course, it’s likely that some people took more than one dose, said Bikram Subedi, an analytical chemist at Murray State University in Kentucky and one of the study’s authors. Moreover, he added, some of the drugs used on eclipse day likely came from visitors who came to see the eclipse, not the town’s regular population.

“This is an interesting study and provides valuable information on the magnitude of increase in the use of illicit drugs during specific holidays,” wrote Kurunthachalam Kannan, an environmental health researcher at the Wadsworth Center, New York State Department of Health in Albany, New York, in an email. “One interesting find is that meth usage in communities surveyed seems to be higher than in urban communities.” Kannan was not involved in the study.

Researchers have used sewage to track drug use in other parts of the world, but the technique has rarely been used in the United States, despite its potential to complement traditional data sources such as surveys and toxicology reports, said Subedi. Sewage can’t lie like a person on a survey, and it offers a relatively unbiased look at all drug use in a community, not just the extreme cases that end up in a hospital. And unlike traditional methods, sewage analysis can track changes from day to day.

“This will give the semi-real-time drug consumption in communities,” said Subedi. “That information could be really helpful for the authorities.”

By Rafi Letzter

There’s a lot of cocaine and heroin in the world, and there’s a pretty good chance you’ve got a tiny bit of it on your body right now — even if you’ve never knowingly touched the stuff.

That’s the conclusion of a new paper published in the journal Clinical Chemistry today (March 22), which found that 13 percent of drug-free study participants had traces of the drugs on their fingertips. The participants, residents of the United Kingdom tested at the University of Surrey, didn’t have enough heroin or cocaine on their fingers for it to be visible, and certainly not enough to get them (or anyone) high. But they did have enough cocaine or heroin on their hands to trip very sensitive instruments called mass spectrometers.

But the point of the study wasn’t just to reveal that there’s a whole lot of trace narcotics floating around out there.

Instead, researchers were trying to establish a baseline for how much trace heroin or cocaine would turn up in a non-drug user’s fingerprint. (When a person does a fingerprint test, some of the substances on their fingertips are transferred to the print.) They compared non-drug users’ fingerprints to the fingerprints of recent heroin or cocaine users, in hopes of establishing a level over which they could confidently say the fingerprint belonged to someone who had recently used drugs.

While they did arrive at such a cutoff, they also found that there’s a lot of environmental contamination on people’s fingers — and that it doesn’t go away when study participants wash their hands.

Chemists already knew that trace amounts of cocaine and heroin are everywhere, said Rolf Halden, director of the Biodesign Center for Environmental Health Engineering at Arizona State University.

“Think of cocaine on paper money,” Halden told Live Science. “We know that a lot of currency is contaminated with cocaine.”

Halden would know: His lab collects sewage water samples from all over the world and tests them for traces of drugs. While most people might not admit to using drugs, he can tell how much certain drugs are actually getting used in a given city based on the traces they leave in the sewage system.

Still, Halden said, the fingerprint finding is new and interesting, and could represent a method of quick drug testing that’s less invasive than drawing blood or collecting hair samples.

That said, Halden cautioned that the results would be much more uncertain than those existing methods. Where people live and which things they regularly touch might lead to a wide range of baseline-level drug traces among different people. A bank teller or tollbooth operator, he speculated, might have much more significant drug traces just from touching cash all day.

“If I’m a lawyer and my client tested for drugs this way, this would be an easy way out [of a conviction],” he said. “I predict it could be potentially helpful [for drug testing], but it would not very rapidly replace other types of testing, like bodily fluids.”

While it might surprise readers to learn they have a reasonably good chance of having drugs they’ve never used on their fingertips, Halden said it’s nothing to worry about.

“The levels are way too low to be consequential,” he said.

The reality is that chemists’ instruments are so sensitive that they can detect even the tiniest traces of substances.

“We also can detect a lot of prescription drugs in drinking water,” Halden said. “There [are] a few molecules in there — enough for us to detect them as analytical chemists, but not enough to have a measurable impact on people.”

In other words, no one’s getting high from finger-molecules of old cocaine on their banknotes. And they don’t represent any kind of individual danger to anyone.

That said, Halden added, there just isn’t enough data yet to know if there might be some kind of population-level effect from this kind of widespread contamination. But if it’s there, he said, it’s vanishingly subtle — to the point of having zero measurable effect on any one individual — and people should not worry about it.