[Chemistry Class Notes] Forensic Chemistry Pdf for Exam

Forensic Chemistry is the method where you apply Chemistry to assist in examining unknown materials found at a crime scene. This is done legally and chemists have a wide range of instruments and methods to use for this purpose.

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What Does a Forensic Chemist do?

The role of a forensic chemist varies a lot. Primarily, they work in a lab and are hired either by the government (local, state or central) or a private investigation firm. In the lab, they test samples that are collected by detectives and investigators. These chemists are generally trained in organic Chemistry and physics. Organic Chemistry helps in letting the Scientists run analysis on body samples to identify DNA. They also run toxicology screenings.

Wide knowledge of Physics is required in this field. Although chemists mostly work in labs, sometimes a forensic chemist who is familiar with physics is called into the crime scene to examine things such as blood patterns, the range of attack, whether the injury was intentional or accidental, etc. Chemists can also specialize in certain aspects such as arson-related chemicals which can be used to make fire or bombs (explosives).

Role of a Forensic Chemist

If you ask what forensic chemists do, here we try and explain who are forensic chemists and what involves their primary duties. A forensic chemist collects and analyses substances found in a crime scene and tries to map out how it might be related to the crime. There are various types of forensic chemists who specialize in certain aspects. These Scientists use Chemistry and involve trace materials, drugs and other substances to help solve crimes. 

In addition to this, they also use biology and physics to analyze samples and the crime scene. They use ultraviolet or infrared light, X-ray spectroscopy, Chromatography (gas, column, etc), and mass spectrometry as their analytical instruments to find evidence. They first try to use reversible methods to preserve the original samples so that they can carry out more tests if required.

Methods used in Forensic Chemistry

There are several processes and methods used by forensic chemists when they carry out their work, Spectroscopy and Chromatography are the two main processes used in this field.

Spectroscopy: It is the study of absorption and emission of light and other radiation by matter which is dependent on the wavelength of the radiation. It also refers to the interactions between electrons, protons and ions, and their interaction with other particles as related to their collision energy. It can be used when the sample is pure or a very common mixture. 

The main techniques are FTIR and AA. FTIR is a non-destructive process that uses infrared light to identify a substance. This is a quick and easy step in the analysis of some unknown substances. AA or Atomic Absorption Spectroscopy is a destructive technique that can be used to determine the elements that make up an analyzed sample. It is analyzed by putting the sample in an extremely high heat source, thus breaking the atomic bonds leaving free atoms. This is exposed to radiation which makes the atoms move to a higher state and then check the corresponding wavelength associated with it. Due to the destructive nature of this method, it is generally used as a confirmatory technique.

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Chromatography: It is a process used to separate components of a mixture. The mixture is first dissolved in a substance called the mobile phase. Then, the mobile phase carries it through a second substance called the stationary phase. This leads to the separation of the mixture into two or more components. This technique is used for analyzing unknown mixtures which are broken down into individual parts allowing them to be examined separately. 

Thin-layer chromatography (TLC) can be used to analyze inks and dyes by extracting most of the individual substances. This is used to investigate notes or fibers left at the scene as the fabric company products have a slight difference and the cloth could be traced back to its buyer. High-performance liquid chromatography (HPLC) is used to extract non-volatile mixtures dissolved in a solution which would not be suitable for gas chromatography. This is useful in drug analysis. Gas chromatography (GC) performs the same function as liquid chromatography but for volatile mixtures. They can be used for investigations related to arson, poisoning, explosions, etc.

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Why a Forensic Chemistry Degree?

Forensic chemists have a wide range of areas that they can jump into after acquiring their degree.

Your degree may also be useful in jobs like:

Tips to prepare for Forensic Chemistry

Let’s get to know some of the tips to prepare well for the subject of Chemistry. 

You need to understand that thinking of an answer and writing it out on a piece of art isn’t the same. And a test may be a very bad place to realize it. You need to work on the problems and theory part and write it down on paper before you go for the test. It is similar to a musician being in a live concert and realizing that you can’t sing a particular song which just started. In Chemistry, you must work it out for yourself in writing. Hence, students shall be very considerate of this one. Make sure that whenever you learn something new, you keep a pen and paper near you. It might sound weird to most of you and look like a time-consuming task but you shall realize that it guarantees lifelong learning. It is because once you write something, it registers in your mind and you can remember it for a longer time. 

Isn’t it foolish for a person to not practice the whole year and then cram a night before the exam? Many students believe that learning only the night before is sufficient and this will help to pass the exam. But this is wrong, you need to take note of it that studying only the night before may tire your brain which is not good for you and your result. And also a major drawback is that you will not be able to have enough sleep which may cost you a lot. You should be consistent with your studies and not just leave it for exam time. Practicing daily will help you get better conceptual clarity. And also an important point, you should not be hesitant in taking breaks, take a short break and return with a calm mind.

What you need to aim for is your best and not competing with any other student. You just need to maintain a competitive spirit in you but that too is only for beating yourself. You should try to give your best and not regret in future that you could have been better or done something else. Sloppy work habits will only degrade your performance and that’s exactly what you don’t want for yourself. You will always be unsatisfied if you don’t give your best. Make sure that you always use the right bunch of words that intend what you meant to say. You need to be very careful while choosing the words, if it will mean something else it may cause loss of marks. Also, write all your explanations in a clear and complete sentence. The best way to make sure that you follow all this is by evaluating yourself before the exams. You shall consider attempting mock tests or other quizzes with sincerity and once you’re done, take a note of your results. Ensure that the next plan of action is made based on these observations.

Anxiety is the worst and that too at the time of the test. It can worsen your concentration and also it doesn’t let you do what you really can do. Instead of worrying about it just write your answers with an attitude that you have done it and prepared your best. So keep your calm while attempting the exam and you will surely get the results. Some of the ways to keep a calm mind are by meditating or doing some light exercises. You shall also eat well and keep yourself hydrated so that your body supports your brain to its fuller capacity.

Now when you have gone through with the study material once, then you should start it over again. Reread all the study material available with you, get into the notes again and give your best to attempt the exam. Reading is the most important skill that you should learn. It will help you get better scores. This will also get you more familiar with the material which will help you pass the exam with flying colors. Students shall understand that when you read, you understand and with better understanding, there comes a more confident approach that students can use to make the best out of their potential.