An autosampler is commonly a device that is coupled to an analytical instrument providing samples periodically for analysis. [1] An autosampler can also be understood as a device that collects samples periodically from a large sample source, like the atmosphere or a lake, for example.
Autosamplers enable substantial gains in productivity, precision and accuracy in many analytical scenarios, and therefore are widely employed in laboratories.
An autosampler normally consist of an automated machine or robotic device that can either bring the sample to a sampling station, or bring a sampling device to the sample that stays on a tray (or carousel) along with other samples.
Some autosamplers for solids are used in conjunction with elemental analyzers. [2] Common models consist of a carousel that holds the samples that are commonly wrapped in metal (usually tin or silver) foil. Usually, by spinning by the carousel a fixed number of degrees, a sample falls into the reactor, which is constantly purged by a carrier gas (He, for example). [2]
Other autosamplers for solids can be used for non-destructive analyses as well, like weighing and gamma ray measurements, [3] for example. In these cases, a mechanism brings the sample to the analyzer and, when the measurement is finished, it removes the sample, thus allowing a consecutive measurement.
Autosamplers for liquids work along many kinds of machines that perform different kinds of chemical measurements, like titrators, gas chromatographers, liquid chromatographers, water analyzers (like total carbon analyzers, dissolved inorganic carbon analyzers, nutrient analyzers) and many others.
Many autosamplers for liquids consist of a carousel and the sampling apparatus. The carousel holds the samples, and revolves around its center so that samples change their horizontal position. There may be several concentric rings holding samples in a carousel. The sampling apparatus can be fixed horizontally, only moving up and down to allow the carousel to move, or it can also move horizontally, depending on the design of the system. The sampling apparatus in most of such autosamplers consist of a needle connected to a remote pumping syringe via tubing. Similar designs have been employed for titrators, which do not have a sampling apparatus, but a titration apparatus.
Another common design for autosamplers for liquids is of a sampling apparatus that moves freely in the 3D space, similarly to CNC routers and 3D printers, for instance. The sampling apparatus, in these autosamplers, can also be simply a needle, as for most carousel autosamplers, or it can be a syringe, [4] thus dispensing the need for a remote pump. This kind of design is appropriate for small sample volumes (in the order of tens of microliters), commonly used in gas chromatography, for example.
A less common, but potentially much more affordable, kind of autosampler for liquids is a robotic arm which carries the sample to the sampling tube or needle, or to the titration area. [5]
Autosamplers for gases can be as simple as a pump that continuously sucks air or any gas mixture inside the analytical device, or be the same as the one used for liquids, but with a gas-tight syringe.
Many autosamplers are sold as optional parts of the analytical setup, and make up for a substantial portion of its total cost. It is noteworthy that autosamplers for different devices work in a very similar way and could easily be adopted by different machines. However, this is uncommon as manufacturers often restrict the compatibility of accessories to their analytical setup.
Lack of compatibility between analytical instruments from different manufacturers has been repeatedly recognized as a problem in analytical scenarios. [6] [7] A solution often proposed is the adoption of standards by different manufacturers which would enable machines to communicate between them seamlessly. However, there has been little real progress in this area, despite larger efforts in this direction. [7]
It is noted that many manufacturers incorporate contact closure pins/ports on their autosamplers, which means that the autosamplers are able to communicate with the other parts of most third party chromatography instrumentation.
A different solution for the lack of compatibility between analytical instruments is their coupling by means of scripting. [4] [5] [8] [9] This way, substantial savings are possible.
Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that uses an inductively coupled plasma to ionize the sample. It atomizes the sample and creates atomic and small polyatomic ions, which are then detected. It is known and used for its ability to detect metals and several non-metals in liquid samples at very low concentrations. It can detect different isotopes of the same element, which makes it a versatile tool in isotopic labeling.
A burette is a graduated glass tube with a tap at one end, for delivering known volumes of a liquid, especially in titrations. It is a long, graduated glass tube, with a stopcock at its lower end and a tapered capillary tube at the stopcock's outlet. The flow of liquid from the tube to the burette tip is controlled by the stopcock valve.
Thermal analysis is a branch of materials science where the properties of materials are studied as they change with temperature. Several methods are commonly used – these are distinguished from one another by the property which is measured:
An automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly, with minimal human assistance. These measured properties of blood and other fluids may be useful in the diagnosis of disease.
Karl Fischer titration is a classic titration method in chemical analysis that uses coulometric or volumetric titration to determine trace amounts of water in a sample. It was invented in 1935 by the German chemist Karl Fischer. Today, the titration is done with an automated Karl Fischer titrator.
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.
A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor to measure the effect of incident charged particles or photons.
Laboratory robotics is the act of using robots in biology, chemistry or engineering labs. For example, pharmaceutical companies employ robots to move biological or chemical samples around to synthesize novel chemical entities or to test pharmaceutical value of existing chemical matter. Advanced laboratory robotics can be used to completely automate the process of science, as in the Robot Scientist project.
A gas syringe is a piece of laboratory glassware used to insert or withdraw a volume of a gas from a closed system, or to measure the volume of gas evolved from a chemical reaction. A gas syringe can also be used to measure and dispense liquids, especially where these liquids need to be kept free from air.
Thermogravimetric analysis or thermal gravimetric analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. This measurement provides information about physical phenomena, such as phase transitions, absorption, adsorption and desorption; as well as chemical phenomena including chemisorptions, thermal decomposition, and solid-gas reactions.
A Coulter counter is an apparatus for counting and sizing particles suspended in electrolytes. The Coulter counter is the commercial term for the technique known as resistive pulse sensing or electrical zone sensing. The apparatus is based on the Coulter principle named after its inventor, Wallace H. Coulter.
The AutoAnalyzer is an automated analyzer using a flow technique called continuous flow analysis (CFA), or more correctly segmented flow analysis (SFA) first made by the Technicon Corporation. The instrument was invented in 1957 by Leonard Skeggs, PhD and commercialized by Jack Whitehead's Technicon Corporation. The first applications were for clinical analysis, but methods for industrial and environmental analysis soon followed. The design is based on segmenting a continuously flowing stream with air bubbles.
A refractometer is a laboratory or field device for the measurement of an index of refraction (refractometry). The index of refraction is calculated from the observed refraction angle using Snell's law. For mixtures, the index of refraction then allows to determine the concentration using mixing rules such as the Gladstone–Dale relation and Lorentz–Lorenz equation.
A liquid handling robot is used to automate workflows in life science laboratories. It is a robot that dispenses a selected quantity of reagent, samples or other liquid to a designated container.
Laboratory automation is a multi-disciplinary strategy to research, develop, optimize and capitalize on technologies in the laboratory that enable new and improved processes. Laboratory automation professionals are academic, commercial and government researchers, scientists and engineers who conduct research and develop new technologies to increase productivity, elevate experimental data quality, reduce lab process cycle times, or enable experimentation that otherwise would be impossible.
Moisture analysis covers a variety of methods for measuring the moisture content in solids, liquids, or gases. For example, moisture is a common specification in commercial food production. There are many applications where trace moisture measurements are necessary for manufacturing and process quality assurance. Trace moisture in solids must be known in processes involving plastics, pharmaceuticals and heat treatment. Fields that require moisture measurement in gasses or liquids include hydrocarbon processing, pure semiconductor gases, bulk pure or mixed gases, dielectric gases such as those in transformers and power plants, and natural gas pipeline transport. Moisture content measurements can be reported in multiple units such as: parts per million, pounds of water per million standard cubic feet of gas, mass of water vapor per unit volume or mass of water vapor per unit mass of dry gas.
NeSSI is a global and open initiative sponsored by the Center for Process Analysis and Control (CPAC) at the University of Washington, in Seattle.
The hydrocarbon dew point is the temperature at which the hydrocarbon components of any hydrocarbon-rich gas mixture, such as natural gas, will start to condense out of the gaseous phase. It is often also referred to as the HDP or the HCDP. The maximum temperature at which such condensation takes place is called the cricondentherm. The hydrocarbon dew point is a function of the gas composition as well as the pressure.
A robotic arm is a type of mechanical arm, usually programmable, with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot. The links of such a manipulator are connected by joints allowing either rotational motion or translational (linear) displacement. The links of the manipulator can be considered to form a kinematic chain. The terminus of the kinematic chain of the manipulator is called the end effector and it is analogous to the human hand. However, the term "robotic hand" as a synonym of the robotic arm is often proscribed.
Mettler Toledo is a multinational manufacturer of scales and analytical instruments. It is the largest provider of weighing instruments for use in laboratory, industrial, and food retailing applications. The company also provides various analytical instruments, process analytics instruments, and end-of-line inspection systems. The company operates worldwide with 70% of net sales, derived in equal parts, from Europe and from the Americas. Asian business is included in the remaining 30%. Mettler Toledo is headquartered in Switzerland and incorporated in the United States.