As an organic chemist, I've had a l

As an organic chemist, I've had a lot of exposure to organic solvents, especially the popular dichloromethane, also known as DCM or methylene chloride. Dichloromethane is a volatile, colourless liquid, with a mildly sweet, not unpleasant odour. It’s immiscible with water but can dissolve a wide range of organic compounds. These properties make it the perfect solvent for use in the lab, and indeed that how I used it - to separate and extract organic products.

But it's not just useful in the lab; coffee, a very popular drink amongst researchers, was once decaffeinated using DCM. Unroasted beans would be steamed and then repeatedly rinsed in DCM, which would extract the caffeine. The solvent would then be drained away, leaving behind coffee beans packed full of flavour, but without the buzz. An alternative method was to essentially make a giant pot of very strong coffee, then extract the caffeine using DCM. When a new batch of beans was added to the brew, the higher concentration of caffeine in the beans would leach out into the water, decaffeinating the beans without removing any of the compounds essential to the flavour of the coffee.

DCM was the solvent of choice for caffeine extraction in the 1970s, however when it was found to be carcinogenic it was soon replaced by other non-toxic solvents. DCM is not only carcinogenic, but if it’s inhaled, it can also affect the central nervous system. On one occasion I was 'extracted' from the lab by my supervisor at the end of a long day, as my blushing cheeks and dazed expression revealed how productive I’d been with my own extractions.

‘Although DCM has a toxic dark side, it’s found a light-hearted use in a Chinese toy – the drinking bird’It was a good thing that she did tell me to take a (decaffeinated) coffee break - exposure can be fatal, with the most prominent symptoms being respiratory depression and narcosis. Due to its high volatility, toxic vapours can build up quickly in small spaces, such as bathrooms, if left unventilated. The solvent has unfortunately led to the deaths of several bathtub refinishers, who used DCM as an effective paint stripper. The enzyme Cytochrome P-450 also metabolises DCM in the body to produce carbon monoxide, which could potentially lead to carbon monoxide poisoning.
Although DCM has a toxic dark side, it’s found a light-hearted use in a Chinese toy – the drinking bird. The bird is made from a glass body containing dichloromethane - with two bulbs, representing the head and body, connected by a tube. Drinking birds are heat engines that use a temperature difference between the head and body to convert heat energy to mechanical work. This work takes the form of the bird tipping back and forth, just like it’s drinking from a cup of water.

Drinking birds have featured in many works of fiction to automatically press buttons or set off explosions. In The Simpsons episode ‘King-Size Homer’, Homer leaves a drinking bird in charge of safety at the nuclear power plant, by placing it in front of his computer keyboard while he irresponsibly goes out to watch a film. The bird repeatedly presses the ‘Y’ key to indicate a ‘yes’ in response to the computer prompts and almost causes a nuclear meltdown when it falls over and Homer isn’t around to pick it up.

If he had realised the bird’s peril, he would have balanced it back vertically on its pivot to start the tipping motion again. From this point, water from the bird’s head evaporates, lowering the temperature through the heat of vapourisation. The decrease in temperature causes the dichloromethane vapour in the head to condense, which reduces the pressure in the head according to the ideal gas law. The higher vapour pressure in the warmer base of the bird pushes dichloromethane up its neck, causing it to become top heavy and tip over into the traditional water source, or the keyboard in Homer’s case. The liquid is then displaced back into the base of the bird by the warm DCM vapour rising, thus returning the bird to its original position and the pressure back to equilibrium.

Dichloromethane plays an important part in the mechanism; its low boiling point means the drinking bird can function at room temperature. The bird can move even without a water source, like in the Simpson’s episode, – as long as the body is heated to a higher temperature than the head. Some people believe that the toy is a perpetual motion machine; however this is unfortunately not true, as it uses temperature gradients as an energy source.

So the next time you're enjoying a cup of decaf, taking a bath or thinking about leaving a drinking bird in charge of your work whilst you sneak off on holiday, spare a thought for dichloromethane – the organic chemist’s favourite smelling solvent.

Meera Senthilingam

Science writer Emily James there with the odour-filled chemistry of dichloromethane. Next week, we switch senses from smell to sight and things begin to glow.

Brian Clegg

Of all the potential properties of a chemical substance, probably the most exotic is being able to glow in the dark. When radium was first discovered, its glow was a major selling point (until it was discovered to be deadly), and any compound that can produce a ‘cold light’ safely is bound to attract attention.

Meera Senthilingam

Discover which compound safely enables this by joining Brian Clegg in next week’s Chemistry in its Element. Until then, thank you for listening, I’m Meera Senthilingam.

Kết quả (Anh) 1:

As an organic chemist, I've had a lot of exposure to organic solvents, especially the popular dichloromethane, also known as methylene chloride or DCM. Dichloromethane is a volatile, colourless liquid, with a mildly sweet, not unpleasant odour. It is immiscible with water but can dissolve a wide range of organic compounds. These properties make it the perfect solvent for use in the lab, and indeed that how I used it-to separate and extract organic products.But it's not just useful in the lab; coffee, a very popular drink amongst researchers, was once decaffeinated using DCM. Unroasted beans would be steamed and then repeatedly rinsed in DCM, which would extract the caffeine. The solvent would then be drained away, leaving behind the coffee beans packed full of flavour, but without the buzz. An alternative method was to essentially make a giant pot of very strong coffee, then extract the caffeine using DCM. When a new batch of beans was added to the brew, the higher concentration hand of caffeine in the beans would leach out into the water, the decaffeinating beans without removing any of the compounds essential to the flavour of the coffee.DCM was the solvent of choice for caffeine extraction in the 1970s, however when it was found to be carcinogenic it was soon replaced by other non-toxic solvents. DCM is not only carcinogenic, but if it’s inhaled, it can also affect the central nervous system. On one occasion I was 'extracted' from the lab by my supervisor at the end of a long day, as my blushing cheeks and dazed expression revealed how productive I’d been with my own extractions.‘Although DCM has a toxic dark side, it’s found a light-hearted use in a Chinese toy – the drinking bird’It was a good thing that she did tell me to take a (decaffeinated) coffee break - exposure can be fatal, with the most prominent symptoms being respiratory depression and narcosis. Due to its high volatility, toxic vapours can build up quickly in small spaces, such as bathrooms, if left unventilated. The solvent has unfortunately led to the deaths of several bathtub refinishers, who used DCM as an effective paint stripper. The enzyme Cytochrome P-450 also metabolises DCM in the body to produce carbon monoxide, which could potentially lead to carbon monoxide poisoning.Although DCM has a toxic dark side, it’s found a light-hearted use in a Chinese toy – the drinking bird. The bird is made from a glass body containing dichloromethane - with two bulbs, representing the head and body, connected by a tube. Drinking birds are heat engines that use a temperature difference between the head and body to convert heat energy to mechanical work. This work takes the form of the bird tipping back and forth, just like it’s drinking from a cup of water.Drinking birds have featured in many works of fiction to automatically press buttons or set off explosions. In The Simpsons episode ‘King-Size Homer’, Homer leaves a drinking bird in charge of safety at the nuclear power plant, by placing it in front of his computer keyboard while he irresponsibly goes out to watch a film. The bird repeatedly presses the ‘Y’ key to indicate a ‘yes’ in response to the computer prompts and almost causes a nuclear meltdown when it falls over and Homer isn’t around to pick it up.If he had realised the bird’s peril, he would have balanced it back vertically on its pivot to start the tipping motion again. From this point, water from the bird’s head evaporates, lowering the temperature through the heat of vapourisation. The decrease in temperature causes the dichloromethane vapour in the head to condense, which reduces the pressure in the head according to the ideal gas law. The higher vapour pressure in the warmer base of the bird pushes dichloromethane up its neck, causing it to become top heavy and tip over into the traditional water source, or the keyboard in Homer’s case. The liquid is then displaced back into the base of the bird by the warm DCM vapour rising, thus returning the bird to its original position and the pressure back to equilibrium.Dichloromethane plays an important part in the mechanism; its low boiling point means the drinking bird can function at room temperature. The bird can move even without a water source, like in the Simpson’s episode, – as long as the body is heated to a higher temperature than the head. Some people believe that the toy is a perpetual motion machine; however this is unfortunately not true, as it uses temperature gradients as an energy source.So the next time you're enjoying a cup of decaf, taking a bath or thinking about leaving a drinking bird in charge of your work whilst you sneak off on holiday, spare a thought for dichloromethane – the organic chemist’s favourite smelling solvent.
Meera Senthilingam

Science writer Emily James there with the odour-filled chemistry of dichloromethane. Next week, we switch senses from smell to sight and things begin to glow.

Brian Clegg

Of all the potential properties of a chemical substance, probably the most exotic is being able to glow in the dark. When radium was first discovered, its glow was a major selling point (until it was discovered to be deadly), and any compound that can produce a ‘cold light’ safely is bound to attract attention.

Meera Senthilingam

Discover which compound safely enables this by joining Brian Clegg in next week’s Chemistry in its Element. Until then, thank you for listening, I’m Meera Senthilingam.

Kết quả (Anh) 2:

As an organic chemist, I've had a lot of exposure to organic solvents, the Popular Especially dichloromethane, DCM or am also known as methylene chloride. Dichloromethane is a volatile, colorless liquid, with a mildly sweet, not unpleasant Odour. It's immiscible with water but can dissolve a wide range of organic compounds. These properties make it the perfect solvent for use in the lab, and indeed how I USED mà it - to separate and extract organic products. But it's not just in the lab ích; coffee, drink a very Popular Amongst researchers, was once decaffeinated using DCM. Unroasted beans would be Steamed and then repeatedly rinsed in DCM, mà would extract the caffeine. The solvent would then be drained away, Leaving behind coffee beans packed full of flavor, but without the buzz. An alternative method was to essentially make a giant pot of very strong coffee, then extract the caffeine using DCM. When a new batch of beans was added to the brew, the Higher Concentration of caffeine in the beans would leach out Into the water, decaffeinating the beans without Removing any of the compounds essential to the flavor of the coffee. DCM was the solvent of choice for caffeine extraction in the 1970s, it was found Tuy nhiên khi it was soon to be carcinogenic by other non-toxic thế solvents. DCM is not only carcinogenic, but if it's inhaled, it can cũng the central nervous system hưởng. On one occasion I was 'extracted' from the lab by my supervisor at the end of a day of long, as my blushing cheeks and dazed expression revealed how I'd Been Productive extractions with my own. "Although DCM has a toxic dark side, it's a light-hearted found use in a Chinese toy - the drinking was a good thing bird'It That She did tell me to take a (decaffeinated) coffee break - exposure can be fatal, with The Most Prominent Symptoms being Respiratory depression and narcosis . Due to the its high volatility, toxic vapours can build up in small spaces Quickly, như bathrooms, if left unventilated. The solvent has unfortunately led to the deaths of vài bathtub refinishers, who USED DCM as an effective paint stripper. The enzyme cytochrome P-450 am also metabolises DCM in the body to Produce carbon monoxide, Which Could Potentially lead to carbon monoxide poisoning. Although DCM has a toxic dark side, it's found a light-hearted use in a Chinese toy - the drinking bird. The bird is made ​​from a glass body containing dichloromethane - with two bulbs, representing the head and body, connected by a tube. Drinking birds are heat engines use a temperature difference mà the between the head and body to convert heat energy to mechanical work. This work takes the form of the bird tipping back and forth, just like it's from a cup of drinking water. Drinking birds have featured in many works of fiction to press buttons automatically sets or set off explosions. In The Simpsons episode "King-Size Homer", Homer leaves a drinking bird in charge of safety at the nuclear power plant, by Placing it in front of his computer keyboard while he irresponsibly goes out to watch a film. The bird repeatedly presses the 'Y' key to indicate a 'yes' in response to the computer Prompts Causes a nuclear meltdown and almost falls over and Homer khi it is not around to pick it up. If he had realised the bird's peril, Balanced he would have it back on the its Vertically pivot again to start the tipping motion. From this point, water evaporates from the bird's head, lowering the temperature through the heat of vapourisation. The Causes Decrease the temperature in dichloromethane in the head to condense Vapour mà reduces the pressure in the head theo ideal gas law. The Higher Vapour pressure in the warmer base of the bird pushes up the its neck dichloromethane, Causing it to trở top heavy and tip over Into the traditional water source, or the keyboard in Homer's case. The liquid is then displaced back Into the base of the bird by the warm DCM Vapour rising, thus returning the bird to the its original position and the pressure back to equilibrium. Dichloromethane plays an Important part in the mechanism; the its low boiling point means clustering the drinking bird can function at room temperature. The bird can move without a water source chẵn, like in the Simpson's episode, - as Long as the body is heated to a temperature coal Higher the head. Some people 'believe rằng perpetual motion machine is a toy; Tuy nhiên unfortunately this is not true, as it dùng temperature gradients as an energy source. So the next time you're Enjoying a cup of DECAF, taking a bath or thinking about drinking Leaving a bird in charge của work whilst you sneak off on holiday, spare a Thought for dichloromethane - the organic chemist's favorite smelling solvent. Meera Senthilingam Science writer Emily James Odour-filled there with the chemistry of dichloromethane. Next week, chúng switch to sight and smell senses from things begin to glow. Brian Clegg Of all the properties of a chemical substance potencial, Probably The Most exotic is being thể glow in the dark. When radium was first Discovered, the its glow was a major selling point (off until it was Discovered to be deadly), and any compound can mà Produce a 'cold light' Safely is bound to Attract Attention. Meera Senthilingam mà Discover Safely bật this compound by Joining Brian Clegg in next week's Chemistry in the its Element. Until then, thank you for listening, I'm Meera Senthilingam.