How Does Atomic Absorption Spectroscopy Work?

Atomic Absorption Spectroscopy(AAS) is a quantitative analytical elemental technique that provides the total metal content of the sample and is almost independent of the molecular form of metal in the liquid sample. It analyzes the concentration of elements in a liquid sample based on energy absorbed from certain wavelengths of light. Alan Walsh, a Lancashire-born physicist was the one who worked on determining the small concentrations of metallic elements using spectroscopy. He got this idea in the 1950s while working in his garden. He worked on it for several years and finally convinced the manufacturers to use AAS for metallic determination. The first commercial AAS was launched in the 1960s and since then this technique has established a robust place in the field of analytical techniques.  Principle of Atomic Absorption Spectroscopy The AAS technique is based on the absorption of energy by ground-state atoms in the gaseous state. It states […]

Carla Lowe Murder Case: A Mystery That Took 4 Decades to Resolve

Carla Lowe, a 21 years old lady, was found dead in the middle of Depot Avenue, near the Amtrak station. She was brutally beaten and run over. In November 1983, Carla Lowe waited for the train at the Amtrak station in Delray Beach, Fla. However, she never boarded the train from Pompano Beach. Detectives said at the time they searched the area for hours but never found anyone who had seen or heard anything suspicious. Since then the case has been a mystery. After almost four decades, there has been a break in this cold case with the help of new fingerprint technology. On 29th November 2021, the Delray Beach Police arrested Ralph Williams (59) for the killing of Carla Lowe. He has been charged with first-degree murder. On the day she was found, Ralph Williams was taken into custody on grand theft auto and burglary charges, but they couldn’t […]

Comparison Microscope: Principle, Features & Applications

The invention of the microscope has been a boon in the scientific field which allowed scientists to visualize things or matter or objects which are not visible to the naked eye. The first microscope came into existence with the invention of early microscope, by a Dutch spectacle maker Zacharias Janssen in 16th century. With the passage of time and different needs for visualization, various kinds of microscopes were invented and one of them was the comparison microscope.  The comparison microscope was invented for side-by-side analysis of objects. As the name suggests, it compares two objects simultaneously. It is an instrument that combines two light microscopes side-by-side connected via an optical bridge which facilitates a split view window. It is one of the important instruments used in forensics. Development of Comparison Microscope The comparison microscope was first launched as a prototype in Germany in 1913. However, it was not popularised in […]

Scanning Electron Microscope

Scanning Electron Microscope (SEM) is a type of electron microscope that produces a three-dimensional image of a microscopic object. As the name suggests the microscope forms the images by scanning the surface of the object with the help of a focused beam of electrons. SEM was first developed in 1937 with the contribution of Manfred von Ardenne. However, the first commercial instrument was launched in 1965.  SEM image reveals information like the morphology, crystalline structure, chemical composition, and orientation of materials/components of the sample. SEM requires electrons that have low kinetic energy because the interaction only with the surface up to a few nanometers of depth is required rather than penetrating deep inside the sample. Principle of Scanning Electron Microscope SEM works on the principle that, “When the accelerated electrons with specific amounts of kinetic energy interact with the surface of the sample, the energy is dissipated in the form […]

Famous Scientists of Toxicology

Toxicology is the scientific discipline that deals with the study of poisons or toxic substances and their effects on living organisms. It is a broad field that encloses the application of biology, chemistry, pharmacology, and medicine to study a particular poison and its effects on living beings, especially humans. It is a wide discipline that is being used in many fields such as environmental, clinical, economic, biochemical, regulatory, industrial, genetic, preventive, behavioral, toxinology, wildlife, and forensic toxicology. Forensic toxicology is the discipline that deals with the medicolegal aspect of poison, types of poison, symptoms, and their possible treatment. Section 328 of IPC provides punishment for causing hurt by means of poison or any stupefying, intoxicating or unwholesome drug or other things with the intent to commit an offense (i.e., anything when used in an unwholesome state/composition can act as a poison). Famous Scientists Contributing to Toxicology Toxicology came into existence […]