Methods and Instruments
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AAS. Atomic Absorption Spectroscopy A spectro analytical procedure for the quantitative determination of chemical elements using the absorption of optical radiation (light) by free atoms in the gaseous state, based on the absorption of light by free metallic ions F-AAS. Flame Atomic Absorption Spectroscopy. A liquid sample is nebulised, transformed into an aerosol which is introduced into a spray chamber, and aspirated into a flame where the sample is atomised GF-AAS. Graphite Furnace Atomic Absorption. Uses a graphite-coated furnace to vaporize the sample. Wikipedia AES. Atomic Emission Spectroscopy A method of chemical analysis that uses the intensity of light emitted from a flame, plasma, arc, or spark at a particular wavelength to determine the quantity of an element in a sample The wavelength of the atomic spectral line in the emission spectrum gives the identity of the element while the intensity of the emitted light is proportional to the number of atoms of the element. The sample may be excited by various methods, e.g. ICP-AES. Wikipedia Also called OES as in ICP-OES, Inductively Coupled Plasma - Optical Emission Spectroscopy Alkalinity. P, M and T In Water, depending upon the pH, alkalinity can exist in three forms: carbonate (CO3), bicarbonate (HCO3), or hydroxide (OH). Total alkalinity is the sum of these three forms Alkalinity is measured in water by titrating a sample with a standard acid to a designated pH and is recorded as P, M, or T alkalinity: P alkalinity is titrated with phenolphthalein to pH 8.3 M alkalinity with methyl orange indicator to pH 4.6 T alkalinity with total alkalinity indicator to pH 4.5 An. AnalysesThese are the analyses or tests included on Analysis Requests ordered by clients. They are date-stamped copies of the Analysis Services configured in the LIMS set-up - they'll be completed with results, to be published to clients after verification Laboratory methods are based on established scientific principles involving biology, chemistry and physics. Test methods specifically define the procedures or processes that are to be used. The laboratory scientist carefully follows step-by-step procedures until the end product, a test result, is achieved. Responsible for analysing the samples in the lab and capturing their results truthfully. Analysts often specialise in specific methods and instruments Analyte A substance whose chemical constituents are being identified and measured. Configured as Analysis Services in Bika Biotoxin Substance both toxic and from biological origin, in many forms and can be produced by nearly all living organism types, e.g. mycotoxins by fungi, zootoxins animals and phytotoxins by plants. Biosciences-labs.bham.ac.uk BOD. Biochemical Oxygen Demand The amount of dissolved oxygen required by aerobic biological organisms to break down organic material present in a water sample at specified temperature and time, commonly expressed in milligrams of oxygen consumed per litre of sample over 5 days of incubation at 20 °C Often used as a surrogate for organic pollution of water, say to measure the effectiveness of wastewater treatment plants. Both BOD and COD, chemical oxygen demand, measure the amount of organic compounds in water. COD is less specific, since it measures everything that can be chemically oxidised Refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence The amount of oxygen that can be consumed by reactions in a solution, e.g. the oxygen consumed over volume of solution in mg/L, often to quantify the amount of organics in water, say oxidisable pollutants in surface or wastewater. See BOD Composite Sample Combined from sub-samples, e.g. Surface Water on a dam - several samples are taken at different points on the dam as per say 10 by 10 m grid, and poured into the same container, homogenised and an analysed As opposed to a 'Grab' sample which is the standard way most Samples are taken CRM. Certified Reference Material'Controls' or standards used to check the quality and metrological traceability of products, to validate analytical measurement methods, or for the calibration of instruments. A certified reference material is a particular form of measurement standard. Wikipedia.org Cytology Biology and clinical disciplines focussing on plant and animal cell structure and functions Dumas method A method for the quantitative determination of nitrogen in chemical substances based on a method first described by Jean-Baptiste Dumas in 1826 Instrument automation capable of rapidly measuring the crude protein concentration, and is now replacing the Kjeldahl method for analysis of protein content for food and animal feeds. Wikipedia.org ERP. Enterprise Resource Planner Software that integrates departments and functions across a company into one computer system, enabling various departments to share information and communicate with each other. ERP systems comprise function specific modules designed to interact with the other modules, e.g. Accounts Receivable, Accounts Payable, Purchasing, etc. GC. Gas Chromatograph HS. Headspace Gas Chromatography Uses headspace gas injected directly onto a gas chromatographic column, excellent for the analysis of volatile species in samples that can be efficiently partitioned into the headspace gas volume from either a liquid or solid matrix, particularly amenable to the analysis of trace levels of analytes Heavy Metals Arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and selenium are some of the metals called 'heavy' because of their high relative atomic mass which persist in nature and can cause damage or death in animals, humans, and plants even at very low concentrations, 1 or 2 micrograms in some cases ICP-AES. Inductively Coupled Plasma Atomic Emission Spectroscopy Inductively coupled plasma atomic emission spectroscopy (ICP-AES) uses an inductively coupled plasma to produce excited atoms and ions that emit electromagnetic radiation at wavelengths characteristic of a particular element Also called ICP-OES, Inductively Coupled Plasma - Optical Emission Spectroscopy IRMS. Isotope-Ratio Mass Spectrometry A specialisation of mass spectrometry, in which mass spectrometric methods are used to measure the relative abundance of isotopes, say the ratio between stable isotopes such as 12C/13C or 14N/15N, useful for product authenticity, traceability studies and physiological research. Measuring radiogenic isotopes, the abundances of decay-products of natural radioactivity, is used in most long-lived radiometric dating methods Kjeldahl digestion A method for the quantitative determination of nitrogen contained in organic substances plus the nitrogen in inorganic ammonia and ammonium Other forms of inorganic nitrogen, for instance nitrate, are not included in this measurement. Developed by Johan Kjeldahl in 1883. Wikipedia.org HRMS. High resolution mass spectrometry
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LOD. Limit of Detection The lowest analyte concentration likely to be reliably distinguished from the LOB and at which detection is feasible LOD is determined by utilising both the measured LOB and test replicates of a sample known to contain a low concentration of analyte. www.ncbi.nlm.nih.gov LOB is the highest apparent analyte concentration expected to be found when replicates of a blank sample containing no analyte are tested. LOB = Mean Blank + 1.645 * SD Blank. www.ncbi.nlm.nih.gov The lowest concentration at which the analyte can not only be reliably detected but at which some predefined goals for bias and imprecision are met The LoQ may be equivalent to the LoD or it could be at a much higher concentration. www.ncbi.nlm.nih.gov The Lower Detection Limit is the lowest value to which the measured parameter can be measured using the specified testing methodology In Bika LIMS, results entered which are less than this value will be reported as < LDL. Also see MDL and UDL MALDI TOF Matrix Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry Identification of microbes In MALDI-TOF mass spectrometry, mass-to-charge ratio, m/z, is measured using matrix-assisted laser desorption/ionization, MALDI, as ion source, and time-of-flight, TOF, for mass analysis Materials Testing Techniques used to determine the physical and mechanical properties of raw materials and components, such as Method. See Analysis Methods MIBK. Methyl Isobutyl Ketone Used to extract gold before analysis using AAS MOF. Metal organic frameworks Porous crystalline materials of one-, two-, or three-dimensional MPN. Most Probable Number A method to estimate the concentration of viable microorganisms in a sample by means of replicate liquid broth growth in ten-fold dilutions. Microbeonline.com A technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio The mass spectrum plots the ion signal as a function of the mass-to-charge ratio, used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules. Wikipedia The most common measure of fiber in animal feed analysis, but does not represent a unique class of chemical compounds, measuring most structural components in plant cells, i.e. lignin and cellulose, but not pectin Further analysis such as ADF can be done to determine individual components. Wikipedia.org NIRS. Near-Infrared Spectroscopy A relatively inexpensive and robust spectroscopic method that uses the 780 to 2500 nm near-infrared electromagnetic spectrum,in medical and physiological diagnostics and research, e.g. blood sugar, functional neuroimaging, sports medicine and training, neonatal research, brain computer interfacing, urology and neurovascular coupling Other applications include pharmaceutical, food and agrochemical quality control, atmospheric chemistry, combustion research and astronomy Nitrogen-15 Analysis Diffusion Disk A sample preparation method for the stable isotope analysis of inorganic nitrogen in aqueous solutions or soil, using ARA-MS, a mass spectrometer equipped with an automated Rittenberg apparatus NMR Nuclear magnetic resonance spectroscopy A spectroscopic technique to measure local magnetic fields around atomic nuclei, to determine the content and purity of a sample as well as its molecular structure OM. Organic Matter. Often measured as % Ash ORP. Oxidation-Reduction Potential ORP measures the ability of a lake or river to cleanse itself or break down waste products, such as contaminants and dead plants and animals. When the ORP value is high, there is lots of oxygen present in the water. www.enr.gov.nt.ca PCR. Polymerase Chain Reaction A technique for amplifying DNA, making it easier to isolate, clone and sequence. Inproteomics.com PDA. Photo Array Detection Diode array detectors, DAD, or more specifically HPLC PDA detectors, are used for obtaining spectral profiles from molecular mixtures or chromatographically separated samples, analysing molecules in a flow cell, static solutions, or solids. Ultra-fast, low noise spectral analysis, resolution is determined by the number of diodes deployed over a specific wavelength range. An HPLC photo diode array detector is coupled to eluates of separation devices by molecular weight, hydrophobicity (reverse-phase) or ionic charge, making them important for HPLC. Certain HPLC PDA detectors handle the entire spectrum from the UV at 190nm to the Near IR at 1 micron, whereas others are specifically targeted to the UV, visual or near IR. HPLC PADs offer programmability for processing spectra, utilizing spectral libraries for component identification. Labcompare.com Preservative May be present in a Sample Container at time the sample is placed into the container PSD. Particle-size distribution The particle-size distribution of a powder, or granular material, or particles dispersed in fluid, is a list of values or a mathematical function that defines the relative amount, typically by mass, of particles present according to size. Wikipedia Used in Bika terminology to differentiate it from QC, is carried out by the lab's QA Officer on the full Batch Report of lab observations and results interpretation After passing QA, the Batch goes to the Lab Director to review and publish to the Client QC refers to the quality control measures carried out by analysts and lab managers on Analysis Results the context of standard reference material |
Handy abbreviationsAAS Atomic Absorption Spectroscopy -----------8<------------------------------------------------- RO. Reverse Osmosis Reverse osmosis is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water. Wikipedia.org Set of materials from which a sample type can be associated with in order to correctly derive a testing methodology Australia: NATA has documentation designating a matrix. Sample Types can expand upon these matrices with a finer granularity Sample Medium. The media samples are taken on, e.g. air filters Sample QC Sample quality management itself, not to be confused with analysis results QC: Samples undergo QC to determine its concentration or purity Sample Rounds Sampling done on recurring field trips, e.g. taking regular water quality samples along a certain route of boreholes and rivers Sample Type The type of sample, e.g. potable water or waste water – this will effect the specifications for its results in Bika Parameter for irrigation water quality, a measure of the amount of sodium relative to the amount of calcium and magnesium Scintillation Counting Liquid scintillation counting is the measurement of activity of a sample of radioactive material which uses the technique of mixing the active material with a liquid scintillator, e.g. Zinc sulfide, , and counting the resultant photon emissions. A measure of the variability of a distribution of values. The more the values cluster around the mean, the smaller the SD SID. Sample IDThe unique and sequential ID issued by the LIMS for physical Samples. Not the same as the CSID, the client's own ID for the sample SOP. Standard Operating Procedure Documents that describe a specific method of accomplishing a task that is to be followed precisely the same way every time. Madison.k12 TAMC. Total Aerobic Microbial Count Measured for analyses from sample receipt to verification Titre The minimum volume of a solution needed to reach the end point in a titration Trace Metals The metals subset of trace elements; that is, metals normally present in small but measurable amounts in animal and plant cells and tissues and that are a necessary part of nutrition and physiology. Many biometals are trace metals. Ingestion of, or exposure to, excessive quantities can be toxic. Wikipedia.org Traceability Ability to trace the history of a LIMS object, e.g. an Analysis Request – when was it sampled, received, analysed and by whom The study of friction, wear, and lubrication optimises mechanical functionality and help prolong the life of mechanical equipment through lowering friction or reducing wear of mating components TVC. Total Viable Count A quantitative estimate of the concentration of microorganisms such as bacteria, yeast or mould spores in a sample, the number of colony forming units (cfu) per g (or per ml). A high TVC count indicates a high concentration of micro-organisms which may indicate poor quality for drinking water or foodstuff. In food microbiology it is used as a benchmark for the evaluation of the shelf-life of foodstuffs. Wikipedia.org TYMC. Total Yeast / Mold Count The Upper Detection Limit is the highest value to which the measured parameter can be measured using the specified testing methodology. In Bika LIMS, results entered which are greater than this value will be reported as > UDL. Also see LDL and MDL WS. WorksheetA collection of analyses grouped together to be executed at the same work station, on the same instrument or by the same analyst. QC Samples are included on WSs for easy verification of Analyses in context XRD. X-ray Crystallography Often used in pharmaceutical labs. An experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. Wikipedia |
