Oxygen --- Identification of Water Pollution

"Do you know why do we need to measure the oxygen concentration in the water?"
"To test whether it is enough for the fish to breath?"

Ok that was a sample answer most probably will be given by normal people who are not into Chemistry or Water Science. The basic knowledge that we know about oxygen is, all living things need oxygen to breath and stay alive. From the perspective of Environmental Science, the oxygen concentration in the water means something more, and we call the oxygen 'dissolved oxygen' (DO). Oxygen is soluble in water, that's why aquatic life can breath underwater!

(image taken from Michael Prescotts's Blog)

BPA - Why Our Plastic Bottles Need to Be BPA free?

(image taken from Clean Body Living website)

We often notice this sign saying 'BPA free' when we walk down the aisles of hypermarket displaying various types of plastic drinking bottles. It seems like a must for the prestigious plastic bottle manufacturers today to put the sign on their products so that customers will be like 'oh ok, BPA must be something nasty, since it says it is free from this substance, it must be safe to use', without actually knowing what BPA is.

Back to 1891...

BPA stands for bisphenol A, a chemical substances that is used in manufacturing of polycarbonate plastic (PC) derived from petroleum. It was first synthesized as early as 1891 by a Russian chemist named Aleksandr Dianin (but it was first mentioned in scientific paper in 1905 by Thomas Zincke from Germany, and of course it was written in German that I couldn't understand the content). Only after over 60 years, in 1953, two scientists - Dr. Hermann Schnell and Dr. Daniel Fox - respectively discovered PC through the reaction between BPA and phosgene. Both of them were amazed by its durability and strength, and continued developing this polymer. At the beginning, this material was used in electrical and electronic appliances and then slowly moved into industries producing plastic bottle and lining of canned food.

How to Get the Heavy Metal Out of the Soil for Analysis - BCR Sequential Extraction

Some time ago I have shared information about heavy metal analysis (simple introduction & more detailed one). Basically the samples we use for those machines are in liquid form so that they can be vaporised followed by being atomised or ionised, then the machines will do the rest. How about solid sample such as soil? Sometimes spillage happens or maybe the natural content of heavy metal in the soil is much higher that it can be harmful to human health. There are a few digestion methods (yes it is called digestion, like how we digest the food to obtain the nutrients) can be used, and this one, this 3-stage BCR sequential extraction method is one of the most basic ones.

(photo taken from Bonnie Plant website)

To make it simple, the same soil will go through 3 times of digestions using different solvent respectively to target heavy metals in different forms for several hours on a shaker to mix well(or overnight, depending on the stage), then it will be centrifuged (spun with high speed to separate the soil from the solvent) so that we can obtain the solvent which will be analysed later on. After we are done with each stage, the soil will be 'washed' with distilled water before the following stage can be carried out to remove the solvent in previous stage to avoid contamination (but remember not to loss any of the soil during the process!). Even though we have carried out the 3 stages of digestion, there still will be some residual heavy metal that is bound to the soil and is not removable with the above methods. Since they are tightly bound, we can ignore them as they can't really move around in the soil and will not bring much impact to us. For this whole process, only 1 gram of oven-dried soil is needed!

Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)

When it comes to analytical chemistry for inorganic elements especially metals, it is almost impossible to not include Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). Compared to simpler laboratory analysis that we have done during matriculation and first year such as titration or measurement using portable meter, the usage of AAS and ICP-MS is rather complex in terms of the whole mechanism used within the instrument. However, we can precisely know the concentration of element contained by the sample using these two methods with the careful preparation of standard solutions. I have written a similar post regarding heavy metal analysis technology last year, but this time we are going to look into the details to understand better how they work behind the shell of the machines.

(Image taken from the website of Avomeen Analytical Services.

Agricultural Expo and UPM 38th Convocation Festival - Environmental Forensic Booth

This was the first time I went to the Agricultural Expo and UPM 38th Convocation Festival held at Bukit Ekspo with the theme 'Agricultural Innovation Centre of Living'. It is an annual event which will be held during the convocation period with exhibitions by various faculties and departments of UPM. Me and Erika spent around two hours there to explore the contribution of UPM mainly in the agricultural sectors. Here's the photo blog of some of my findings there.

The exhibition bus by UPM Research Centre about city agriculture.

The inside of the exhibition bus. Products made of extract of plants are exhibited (these products are not commercialised yet). Information regarding the medical usage of traditional plants are being shown as well. The person in-charged there was very helpful in giving explanation about those plants. It's really eye-opening that actually plants that we might easily oversee bring health benefits.

Introduction to Emerging Contaminants (ECs)

(Image taken from Clean Water Action website)

Water is one of the most vital components in human life that 3.4 millions people die each year due to water-related diseases, which is more than the lives claimed in wars. During the 19th century, one of the water-borne diseases named Cholera spread from Ganges delta in India throughout the world that it created another 6 subsequent pandemics which killed millions of people from all continents. Around 430 - 424 B.C.E., it is believed that Typhoid fever wiped out one third of the population of Athens, bringing the Golden Age of Pericles to an end. Besides the diseases related to water contaminated by bacteria, mosquito-borne diseases such as Malaria and Dengue which are discovered since 2700 B.C.E. and 265 C.E. respectively are also closely-related to our water since mosquitoes require stagnant water to breed. At around 20th century, contamination of water by heavy metals such as lead and mercury is being taken seriously since after the incidents of lead and mercury poisonings.

Chemical Warfare - What is it?

The Nobel Peace Prize 2013 awarded to the Organisation for the Prohibition of Chemical Weapons (OPCW) was announced on 11 October 2013 which was last year but it is brought into the limelight on internet in Malaysia recently when Mohd Nasarudin Mohd Yusof, one of the members of OPCW was discovered as a Malaysian. OPCW is an organisation established in 1997 with 190 Member States today to implement the Chemical Weapons Convention (CWC) to prevent the misuse of Chemistry in warfare. According to the OPCW website, the Convention contains four crucial provisions:

• destroying all existing chemical weapons under international verification by the OPCW
• monitoring chemical industry to prevent new weapons from re-emerging
• providing assistance and protection to States Parties against chemical threats
• fostering international cooperation to strengthen implementation of the Convention and promoting the peaceful use of Chemistry

Chemical warfare icon.
(Image taken from Icon Finder website)

We might be not familiar with chemical warfare in Malaysia but I am sure that most of us have heard of the sinister Agent Orange used by the United States military during Vietnam War to destroy trees foliages that provide covers for the enemies. This example of chemical warfare has portrayed the impacts of chemical weapon usage towards not only the human health, but also the environment. Compared to the spraying of chemical insecticides for example, chemical used in warfare comes in gallons, an amount so huge that can create mass destruction which might last for a very long time. Before the implementation of CWC, Geneva Protocol was signed in 1925 to prohibit the use of chemical and biological weapons due to their horrifying impacts on human and environment. The first use of  chemical agents in war was during the World War I while one of the most recent ones was in 1995, the attack on the Tokyo Subway.

Although the target of the chemical used is human, it is unavoidable that the chemical released brings an impact on the surroundings. Plants might not be able to survive with the presence of the huge amount of foreign chemicals. Animals, which are biological organisms like us, suffer from the effects of mustard gas and cyanide (types of chemical agents used in warfare) as well. Not all the chemicals are deadly, but they will certainly cause lots of sufferings such as blister and chocking. The chemicals might seep into the soil and linger around for a long time, causing the effects to persist for generations. In the past, even after the war ended, the elimination of the unwanted chemical weapons was done by dumping all the toxic chemicals into the ocean, which was the cheapest way to get rid of them. The chemical that was enclosed in bullet or shell eventually leaks due to erosion and gets carried away by ocean waves to everywhere.

War is never a good thing. At least the banning of chemical and biological warfare is a step forward to a better life in terms of humanity.

(Image taken from Live Leak website)

Extra readings:
Reaching Critical Will website - Chemical Weapons
Nuclear Age Peace Foundation website - Chemical and Biological Weapons: Use in Warfare, Impact on Society and Environment