P&R Labpak - Everything for your laboratory

P&R Labpak - Everything for your laboratory
Our Head Office in St Helens

Friday, 19 December 2014

Christmas Closure

P&R Labpak closes on Wednesday 24th December 2014 and re-opens on 5th January 2015. There will be no deliveries during this period.

P&R Labpak would like to take this opportunity now to thank you for your custom this year, and look forward to continuing our relationships in 2015.

We hope you've enjoyed our blog posts over the last year and hope you will continue to read them in future.  If you want us to feature anything or try and answer a question for you then let us know.

Remember to LIKE us on Facebook and subscribe to our Twitter feed too!

Friday, 12 December 2014

Glow Sticks!

A glow stick is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light through chemiluminescence, so it does not require an external energy source. The light cannot be turned off, and can be used only once. Glow sticks are often used for recreation, but may also be relied upon for light during military, police, fire, or Emergency operations.

Chemistry of Glow Stick Colours
A glow stick contains two chemicals and a suitable dye. The chemicals inside the plastic tube are a mixture of the dye and diphenyl oxalate. The chemical in the glass vial is hydrogen peroxide. By mixing the peroxide with the phenyl oxalate ester, a chemical reaction takes place, yielding two molecules of phenol and one molecule of peroxyacid ester (1,2-dioxetanedione). The peroxyacid decomposes spontaneously to carbon dioxide, releasing energy that excites the dye, which then relaxes by releasing a photon. The wavelength of the photon—the color of the emitted light—depends on the structure of the dye.

As stated by the excellent article by Compound Interest, a range of different chemicals can be used, including those shown above, as well as one or two additional dyes. Whilst the molecules of the dye are always present in the solution, the hydrogen peroxide and the diphenyl oxalate are slowly used up by the reaction, until one runs out and the reaction ceases – and it’s at this point that the glow stick will stop emitting its glow.

Friday, 5 December 2014

Christmas Tree Needle Drop

It's that time of year when we think about whether to get a 'real' Christmas tree or whether to get the artificial one out of the loft to decorate.

One of the problems of real trees is needle drop.  First you have to decorate the tree without getting too many injuries from the sharp needles.  Then you have to face the task of collecting the fallen needles on the carpet as the tree slowly withers.

Scientists have looked into the problem of needle drop.

Researchers identified a plant hormone, ethylene responsible for needle loss in balsam fir. They made the discovery by placing fir branches in containers of water inside a growth chamber. After ten days the branches began to produce ethylene and three days later the needles began to drop. After 40 days, the branches were completely bare.

To test that the needle loss was in fact due to the ethylene, the researchers used two chemical compounds that interfere with this hormone: 1-MCP and AVG. After exposing the branches to one of these two products, the needle retention period rose to 73 and 87 days, respectively.

It should be possible to dissolve AVG in the water added to the tree stand, which would prolong the tree's lifespan indoors.  Any Ethylene inhibitors should work.

There are other ways to prolong the life of your tree.

Choose your tree carefully.  Norway spruce (traditional choice but with a quick needle drop rate); Nordmann fir (dark green and expensive but also boasts of a slow needle drop); Noble fir (the king of Christmas trees and again holds a better track record of needle drop than the Norway spruce); Fraser fir (excellent needle-holding properties and a lovely pine fragrance to boot and resembles the Norway spruce).

Make a new cut on the stump when you first buy it or get it home, at least an inch above the previous cut. Put the tree in water immediately, and maintain the water level. Keep temperatures in your home slightly cooler, if possible, and position the tree away from the kitchen. Also, keep fruits away from the tree as they give off ethylene. Lastly, leave the lights on at night. Being left in the dark causes a tree to respire more, using up its carbohydrates. As a result, says Dr. Raj Lada of the Christmas Tree Research Center, "it can be starved to death."

Above all else - decorate and enjoy - don't eat all the chocolates on the tree before Christmas!

For more information visit:-

Friday, 28 November 2014

The livestream below is from one of the four commercial, off-the-shelf high-definition cameras, which take turns streaming a live video feed of Earth for online viewing.

As NASA says, "The cameras are enclosed in a temperature specific housing and are exposed to the harsh radiation of space."

"Analysis of the effect of space on the video quality, over the time HDEV is operational, may help engineers decide which cameras are the best types to use on future missions."

The system is operated one camera at a time on an automated repeating cycle so that the video follows a location on Earth as the ISS passes over, all with no intervention from human operators. It also drops out relatively frequently due to loss of Ku-band transmission, and it goes completely dark while in the night sections.

It's fascinating to watch and is strangely relaxing.  Enjoy!

Broadcast live streaming video on Ustream

Black Scenes = Night side of the Earth

The live video feed from HDEV will occasionally be unavailable due to loss of Ku-band transmission from the International Space Station. Please check the site again in approximately 30 minutes

Friday, 21 November 2014


An analgesic, or painkiller, is any member of the group of drugs used to achieve analgesia — relief from pain. The word analgesic derives from Greek ἀν-, "without", and ἄλγος, "pain.

There are two main types of painkiller - opioids and non-steroid anti-inflammatory drugs (or NSAIDs).  The type of medicines that you need to treat your pain depend on what type of pain you have.


Analgesic drugs act in various ways on the peripheral and central nervous systems. They are distinct from anesthetics, which reversibly eliminate sensation, and include paracetamol (known in the US as acetaminophen or simply APAP), the non-steroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, and opioid drugs such as morphine and oxycodone.

The exact mechanism of action of paracetamol/acetaminophen is uncertain but appears to act centrally in the brain rather than peripherally in nerve endings. Aspirin and the other non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases, leading to a decrease in prostaglandin production. In contrast to paracetamol and the opioids, this reduces not only pain but inflammation as well.
The graphic below from Compound Interest takes a look at a selection of common painkillers, their common brand names, and how they work.

Click to enlarge

For pain associated with inflammation, such as back pain or headaches, paracetamol and anti-inflammatory painkillers work best.

If the pain is caused by sensitive or damaged nerves, as is the case with shingles or sciatica, it is usually treated with tablets that are also used for epilepsy and depression. These tablets change the way the central nervous system works.

The aim of taking medication is to improve your quality of life. All painkillers have potential side effects, so you need to weigh up the advantages of taking them against the disadvantages

For more information visit:-

Friday, 14 November 2014


Platinum has the chemical symbol Pt and atomic number 78. It’s a dense, malleable, ductile, highly unreactive, precious, grey-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver”.

Platinum occurs in the wild as the pure element as well as alloyed with iridium, known as platiniridium.  It is one of the rarest elements in the Earth's crust with an average abundance of approximately 5 μg/kg.

In addition to its high density, resistance to oxidation and other desirable qualities, platinum is remarkably chemically unreactive. For these reasons, a 90-10% alloy of platinum-iridium is still used as the International Prototype Kilogram. Originally, this prototype kilogram was made of pure platinum, but iridium was added to increase its hardness while retaining platinum's many desirable qualities.

Platinum Nuggets

Platinum is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum resistance thermometers, dentistry equipment, and jewellery. Being a heavy metal, it leads to health issues upon exposure to its salts, but due to its corrosion resistance, it is not as toxic as some metals. Some compounds containing platinum are applied in chemotherapy against certain types of cancer.

Platinum;s resistance to wear and tarnish is well suited to its use in fine jewellery.

Platinum is obtained commercially as a by-product from nickel and copper mining and processing.  As an example, of the 245 tonnes of platinum sold in 2010, 113 tonnes were used for vehicle emissions control devices (46%), 76 tonnes for jewellery (31%). The remaining 35.5 tonnes went to various other minor applications, such as investment, electrodes, anticancer drugs, oxygen sensors, spark plugs and turbine engines.

For more information visit:-