Analytical chemistry

Analytical chemistry is the part of chemistry that focuses on finding out what a substance is, how much of it there is, and what it is made of. It helps scientists figure out exactly what’s in a sample and in what amounts. A simple job would be to see how much zinc is in a piece of brass. This type of chemistry is very important in many fields. It is used in medicine to check drugs, in the environment to test air and water, in crime labs to study evidence, in factories to make sure products are safe, and in food testing to check for harmful chemicals.^[1]

Analytical chemistry is usually split into two main parts. Qualitative analysis is about finding out what substances are in a sample.^[2] Quantitative analysis is about measuring how much of each substance is there.^[3] Today, scientists often use tools that can do both at the same time. These tools help them get more detailed and accurate information. To study samples, analytical chemists use many different methods. Some popular ones include spectroscopy (which looks at how substances interact with light), chromatography (which separates substances), electrochemistry (which studies how substances use electricity), and mass spectrometry (which looks at the weight and charge of particles). They also use older methods like titration and weighing to find out what’s in a sample. Each method uses different properties, like how something absorbs light or conducts electricity, to help scientists learn more about what’s in a material.^{[4][5][6][7][8]}

Instrumental analytical chemistry uses advanced machines to study chemicals, and it has changed the way scientists work. These tools are very sensitive, meaning they can find even tiny amounts of substances. They can also study complicated mixtures and track chemical changes as they happen. There are many common techniques.

• HPLC (high-performance liquid chromatography) and GC (gas chromatography), which separate different parts of a mixture.^[9][10]
• AAS (atomic absorption spectroscopy) and UV-Vis spectroscopy, which look at how substances absorb light.^[11][12]
• NMR (nuclear magnetic resonance) and FTIR (Fourier-transform infrared spectroscopy), which help identify molecules based on how they behave under certain conditions.^[13][14]

Some tools combine methods to get even better results. For example, GC-MS (gas chromatography-mass spectrometry) and LC-MS (liquid chromatography-mass spectrometry) both separate substances and then identify them. These powerful machines are used in science labs, hospitals, factories, and more to make discoveries, test products, and solve problems.^[15][16]

Analytical chemistry also focuses on making sure the methods used to collect data are reliable and trustworthy. This is very important in areas like medicine and environmental testing, where accurate results can affect people’s health and safety. Scientists work hard to create and test methods that are precise (they give the same result each time), accurate (they give the correct result), sensitive (they can detect even tiny amounts), specific (they only measure what they are supposed to), robust (they still work well under different conditions), and reproducible (other scientists can get the same results). New tools and technologies are making analytical chemistry even more powerful. Tiny lab-on-a-chip systems, special sensors called biosensors, and smart computer programs using machine learning are helping scientists do faster and more detailed testing. These advances are making it possible to study smaller samples, test many things at once, and get results in real time.^[17]

Analytical chemistry has come a long way over time. In the beginning, scientists used simple methods like flame tests (where flames change color based on the substance) and precipitation reactions (where solid forms in a liquid) to find out what materials were made of. These were mostly qualitative techniques, which helped identify substances. In the 1800s and 1900s, scientists like Robert Bunsen, Gustav Kirchhoff, and Fritz Haber made big discoveries that helped shape modern analytical chemistry. Because of their work, new methods like spectroscopy (using light to study substances) and electrochemistry (studying how substances react with electricity) were developed. Today, analytical chemistry uses advanced tools and is one of the most high-tech parts of chemistry. It plays a major role in many fields, including medicine, nanotechnology, environmental science, and more.^[18][19]

• Environmental chemistry
• Physical chemistry