As technology develops, machines that are able to detect previously unknown substances faster and more accurately are being constructed. Approximately 66% of all products delivered in the United States use chemical analysis of some sort. Instrumental chemistry is a field of chemistry that focuses on the modern machines and methodology used in chemical analysis. The two common methods of instrumentation are spectroscopy and mass spectrometry.
An instrument is a device providing communication between the system being analyzed and the person performing the analysis. Analytical lab instrumentation quantitatively and qualitatively interprets the physical and chemical characteristics of a sample. Qualitative methods reveal information about the sample on a molecular or atomic level. Quantitative method gives information in numerical form about the sample’s components. They typically need a source of energy in order to generate a response capable of being read.
The characteristic or property containing the information of interest is known as a data domain. Information is encoded in numerical form. Data domains are divided into non-electrical and electrical. Some examples of properties that may be measured are density, fluorescence, conductivity, and light absorption. A bit is the basic unit of information within the domain. Three types of analytical devices are detectors, transducers, and sensors. Detectors indicate or record any change in environment. A transducer changes information in nonelectrical domains to information in electrical domains and also does the reverse. Sensors are devices that allow for the observation of chemical species in a continuous and reversible manner.
A critical part of instrumental analysis is the calibrating of instrumental methods. Calibration establishes a relationship between an analytical response and the analyte concentration. It helps to endure that an instrument is operating correctly. Calibration may feature three kinds of limits: the limit of detection, the limit of quantitation, and the limit of linearity. The limit of detection is the lowest possible substance quantity that can be determined from the absence of that substance within a known confidence level. The limit of quantitation is the minimum amount of analyte by which someone can determine the difference between two different amounts of analyte. The analyte amount range by which a response changes is known as the dynamic range. A calibration curve is mapped on an x-y axis, with the solution concentration mapped horizontally and the variable being observed recorded vertically.
Microprocessors and microcomputers are computerized instruments. A microprocessor is a wide scale integrated circuit containing millions of transistors, resistors, and other elements. They are often used to implement operational control of analytical instruments. Microcomputers are made up of combined microprocessors providing functions such as timing, memory, and output. Computerized instruments in offline mode are mainly used to collect and transfer data to a computer for processing. An online computer can work directly and communicate with an analytical instrument. Most modern analytical instruments are embedded with capability to function with a computer. This inline operation allows information to be transferred to a computer at the same time that it is created by the instrument.
Instrumental analysis is often utilized in environmental, medical, and food industries. It is a way of providing assurance of a substance’s quality, safety, and consistency that affect people’s everyday lives. Rapid technological developments in the field continue to push this science into new and exciting fields.