A Brief History of Analytical Chemistry
While the roots of analytical chemistry can be traced back to the 17th century, Izaak Maurits Kolthoff (1894–1993), a Dutch-born American scientist and educator whose work spanned nearly 80 years, is considered the father of the modern form of this science. He brought cohesion and scientific principles into the diverse, unconnected and largely empirical methods of chemical analysis that existed in his time and helped them advance into forms as we know and use today. As a result, while in the early 1900s, Analytical Chemists may have been deemed laboratory technicians rather than scientists, they are now the source of critical information to healthcare, environmental studies, forensics, food & drug safety and other areas.
Analytical chemistry continued to develop in the late 18th century, with French chemist Antoine-Laurent Lavoisier establishing the law of conservation of mass in chemical reactions and coauthoring the modern chemical nomenclature. Based on his experimental work, he determined that chemical reactions with “oxygen,” as named by him, cause combustion and respiration. Lavoisier also discovered that water is a chemical compound of oxygen and hydrogen with the formula H2O rather than an element.
German chemists, Carl Fresenius and Karl Friedrich Mohr, helped advance the discipline in the 19th century. The first textbook of analytical chemistry is credited to Fresenius. He also built a laboratory at home where he trained students in gravimetric techniques he had developed. Mohr’s 1855 book on the technique of titrimetry sparked considerable interest in it, and he also created a colourimetric endpoint for silver titrations. His inventions include diverse laboratory apparatus, including the pinch clamp burette, volumetric pipette, cork borer and Mohr’s balance. Mohr is also renowned for his early enunciation of the conservation of energy doctrine.
World War II (1939-1945) brought about vast changes and growth in analytical chemistry as there was increased demand for complex samples of immense sensitivity to be analysed quickly and accurately. However, due to the need to maintain secrecy, developments came into common knowledge only in the late 1940s after the war ended.
Analytical Chemistry in the 21st Century
Today, Analytical Chemists study all types of matter, metals, minerals, food, drugs, biomolecules, such as proteins and nucleic acids, and also soil, wastewater and other complex mixtures. Current advancements in the field are heading to simplifying and automating processes and miniaturising equipment and systems with the help of microelectronics, especially in spectroscopy, while ensuring optimal performance and reliable analytical results. For instance, innovative instrumentation has led to the development of portable benchtop devices, such as pocket-size Raman spectrometers that can be integrated with smartphones, facilitating out-of-laboratory work. Analytical chemistry has also contributed to developing point-of-care sensing devices, such as at-home COVID testing kits.
The introduction of AI (artificial intelligence) modelling and simulation in analytical laboratories and projects aims to improve efficiency and productivity. The success rate of clinical trials progressing to stage two of the drug development cycle is growing with advancements in high throughput screening, supervised learning and deep learning. Computational models save lab and research time and costs while promoting green chemistry by helping conserve resources, such as reagents, lab kits and protective gear.
Branches of Chemistry
- Analytical Chemistry: The science of obtaining, processing and communicating data about the composition and atomic and molecular structure of substances; the analysis or identification of what matter is and its concentration.
- Organic Chemistry: The study of carbon-containing compounds.
- Inorganic Chemistry: The study of inorganic compounds, including metals, minerals, and organometallic compounds.
- Physical Chemistry: The study of chemical interactions, the principles of physics underlying them, and the behaviour of matter on a molecular and atomic level
- Biochemistry: The study of the structure, composition and chemical reactions of living organisms and how the organisms function to control them.
- Environmental Chemistry: The study of air, water and soil contaminants and their impact on human health and ecology.
- Materials Chemistry: The development, characterisation and application of organic, inorganic, polymeric and hybrid materials that possess potentially useful physical or chemical attributes; encompasses solid-state chemistry, polymer chemistry and nanoscience.
- Theoretical Chemistry: The use of quantum, classical and statistical mechanics to understand and explain the structures of chemical systems and correlate and predict their thermodynamic and kinetic properties.
- Computational Chemistry: The use of mathematical models and computer simulations to study chemical processes, reactions and phenomena as well as understand and predict the behaviour of molecules and materials.
- Nuclear Chemistry: The science of nuclear reactions or reactions that happen within atoms, also aiming to enhance the efficiency and safety of nuclear power sources and the storage and disposal of radioactive materials.
What Do Different Types of Chemists Do?
- Analytical Chemists identify, measure and quantify chemical entities in various matrices, including pure substances or mixtures, to determine their structure, composition and nature. They may also develop new evaluation methods.
- Forensic Chemists test and analyse DNA and other evidence to help in criminal investigations. They may be required to appear in court as witnesses and present their findings as testimony.
- Organic Chemists study the structure, properties and reactions of carbon-containing molecules. They also help develop organic substances as ingredients in new commercial products, such as medicine and plastics.
- Inorganic Chemists study the structure, properties and reactions of non-carbon substances, such as metals. They analyse other inorganic substances, such as ceramics and superconductors, to modify, separate or use them to create products or for other purposes.
- Physical Chemists analyse the behaviour of matter and how chemical reactions take place. Based on their findings, they develop theories related to topics such as complex structure formation. They also research potential applications of new materials.
- Theoretical Chemists could be computational or mathematical chemists or chemical informaticians. What is common to them is that they investigate abstract methods to predict the results of chemical experiments. While specialisations differ, many may touch upon some aspects of computer science, such as artificial intelligence.
- Medicinal Chemists engage in drug development and testing by researching and synthesising chemical compounds and helping develop, improve and scale up the manufacturing processes for new drugs. They help develop new techniques to analyse pharmaceuticals, determine drug interaction with other medicines or the body of organisms, and ensure precise amounts of impurity-free and stable drugs in medications.
- Chemists who have taken on the role of Data Scientists assimilate and organise analytical data generated to improve its accessibility constantly. They work on building predictive models/modelling and simulation capabilities and push the boundaries of analytical chemistry to intersect with artificial intelligence (AI) and its applications.
Chemical Analysis
Measurements lie at the core of chemical analysis, categorised into two types based on how assays (procedures to determine the quality or strength of a substance) are conducted.
- Classical or Wet Chemical Analysis: It employs techniques that need a balance but no other mechanical or electronic instruments. The analysis mostly depends on the chemical reactions between the analyte (material being analysed) and a reagent added to it, and the resultant product, perhaps a coloured one or a solid precipitate, which Analytical Chemists detect and measure.
- Instrumental Analysis: It is the more frequently used methodology and employs various instruments besides a balance. The instrumentation may characterise the chemical reaction between the analyte and reagent or measure analyte properties.
Until the end of the 19th century, most assays were performed using classical methods even though simple instruments, including photometers and electrogravimetric analysis apparatus, were available by then.
The use of instrumental analysis, which developed in the 20th century, was further encouraged in laboratories by the development of electronics during World War II, after which digital computers were widely available. However, despite most assays being instrumentally performed, some still require classical analysis.
Quantitative vs Qualitative Analysis
Qualitative analysis measures the quality of the material being analysed. In contrast, quantitative analysis gives the absolute or relative quantity regarding the concentration of one or more substances in a sample or compound.
Principal Stages of Chemical Analysis
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Question formulation
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Identification of which analytes are to be studied
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Selection and standardisation of the analytical procedure
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Feasibility studies to achieve optimal method, as required
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Generating a plan of analysis
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Sampling and ensuring sample integrity
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Sample pretreatment or preparation
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Analysis and calculations
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Data analysis and interpretation
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Validation of method, as required
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Writing up a report or certificate of analysis, as required
The accuracy of the analytical results depends on each stage of the analysis being correctly executed. Some Analytical Chemists prefer to separate the analysis from the assay, which represents the laboratory part of the analysis.
Some Essential Apparatus Used in Analytical Chemistry
- Glassware to measure volume
- Volumetric apparatus for quantitative analysis
- Bomb calorimeter
- Laboratory oven for drying
- Desiccator to store objects in a dry atmosphere
- Chemical reagents
- Analytical instrumentation
- High-speed cameras and thermal cameras
- Weighing balances, pH meters, hot plates, filtration apparatus, thermometers, mixers/shakers, centrifuges, and liquid nitrogen (to freeze and crush samples, reduce reaction temperature, and sometimes to condense and collect gaseous products for analysis
Analytical Chemist vs Lab Technician
While job titles can differ across regions and companies and also depend on the scope of a role, lab technicians are typically assigned specific tasks, mainly running routine chemical analyses on samples at specified conditions and reporting the results. They are also generally in charge of maintaining equipment (instrumentation and apparatus), operating at the right conditions and ensuring consumables are fit-for-purpose and in stock. Lab technicians are likely to hold an associate or bachelor’s degree at the most since their work is not research-based but follows well-defined routes that do not require original thought.
On the other hand, Analytical Chemists exercise their expert problem-solving skills and design capability derived from their comprehensive knowledge of chemistry. With their higher academic qualifications, they can independently conduct wet chemistry techniques, safely use various reagents, measure precise masses and volumes, and carry out complex calculations.
Current Scenario
The employment outlook of a particular profession may be impacted by diverse factors, such as the time of year (for seasonal jobs), location, employment turnover (when people leave current jobs), occupational growth (when new roles are created), size of the occupation, and industry-specific trends and events that affect overall employment.
The job demand for Analytical Chemists is anticipated to grow but at a slower-than-average pace in the current decade. Opportunities are likely to arise in the field of environmental research that aims at reducing pollution and enhancing energy efficiency and pharmaceutical research to develop point-of-care testing (POCT) methods and devices which quickly and accurately detect infectious diseases and other health parameters, such as blood glucose, thereby helping minimise the impact of pandemics and other health concerns, such as diabetes.
Potential Pros & Cons of Freelancing vs Full-Time Employment
Freelancing Analytical Chemists have more flexible work schedules and locations. They fully own the business and can select their projects and clients. However, they experience inconsistent work and cash flow, which means more responsibility, effort and risk.
On the other hand, full-time Chemical Analysts have company-sponsored health benefits, insurance, and retirement plans. They have job security with a fixed, reliable source of income and guidance from their bosses. Yet, they may experience boredom due to a lack of flexibility, ownership, and variety.
When deciding between freelancing or being a full-time employee, consider the pros and cons to see what works best for you.