Instruments

MOL's examination laboratory utilises advanced and specialised instruments in order to make performing requested analyses as precise and fast as possible. Below specified are examples of some of the instruments we use and examples of their usage in our laboratory.

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GAS CHROMATOGRAPHY (GC)

Gas chromatography (GC) is a type of chromatography in which the mobile phase is a carrying gas. An inert gas (like helium) or a non-reactive one (like nitrogen) is typically used. The stationary phase is represented by a microscopic layer of liquid or polymer on a solid inert carrier placed in a glass or metal colon. The instrument used for performing this kind of chromatography is called a gas chromatographer.
Gas chromatography is different from other types of chromatography (HPLC, TLC) in that the sample travels through the colon in gas condition. The interactions of substances in the sample (which are in gas condition) with the walls of the colon (which can be covered with different stationary phases) are the cause of the differing time it takes each substance to travel through the colon, called retention time. The comparison of these retention times makes the analytical strength of gas chromatography.

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GAS CHROMATOGRAPHY – MASS SPECTROMETRY (GC/MS)

Gas chromatography – mass spectrometry (GC/MS) is a method that combines the characteristics of gas-liquid chromatography and mass spectrometry in order to identify different substance in the given sample. GC/MS is used in medication detection, examination of environment samples, as well as for identification of unknown samples. Also, GC/MS can be used as a part of security measures on airports for detection of substances in luggage or on humans.
MS is considered the »golden standard« for identification of substances and because it is used for performing specific tests. A specific test can precisely identify a substance in a given sample. A non-specific test, however, only shows that some given substance belongs to some category of substances.

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HIGH PRECISION LIQUID CHROMATOGRAPHY (HPLC)

High precision liquid chromatography (HPLC) is an excellent method for dissolving, identification and quantitative determination of mixtures of many similar analytes. The resulting chromatogram immediately provides qualitative and quantitative information. Every substance in a mixture has its retention time under specific conditions, whereby both the surface and height of the peak are proportional to the amount of the substance.

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INFRARED SPECTROPHOTOMETRY (IR)

Infrared spectrophotometry (IR) is a method of characterisation of some substance or sample. In this method, a beam of infrared radiation is passed through a space filled with some substance, whereby at individual frequencies a weakening of the light's intensity occurs. Alongside qualitative analyses, IR is also used in quantitative analyses. This metod is especially suitable for quantitative analysis of large series of samples, whereby it is possible to control environment samples, the purity of the products and raw materials in industrial processes... Additional advantages of this method are high detection sensitivity and the possibility of recording spectres regardless of the sample's agregate condition

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SOLID PHASE EXTRACTION (SPE)

This method can be used to remove dissolved organic substances from water solutions by passing the liquid through a cartridge which contains a material that can adsorb the analyte of interest. Our laboratory uses SPE to concentrate and filter the samples that need to be analysed. SPE can be sued for isolating analyte from different matrixes, including urine, blood, water samples, different drinks, soil, animal tissue, different products... This method is more environment-friendly compared to some other extraction methods, due to the use of far fewer solvents.

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ATOMIC ABSORPTION SPECTROMETRY

Atomic absorption spectrometry is a spectro-analytical method for the quantitative determination of chemical elements by using optical absorption of radiation (brightness) free atoms in the gas state. This method is appropriate for the analysis of many metals (more than 62 different metals in the solution) and a few non-metals. It is used for routine analysis of multiple samples for analysis of water (natural and waste), soil analysis, wines, mining and many other analyzes. For analysis using a small amount of sample.

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OPTICAL-EMISSION SPECTROMETRY WITH INDUCTIVELY COUPLED PLASMA (ICP-OES)

Optical-emission spectrometry with inductively coupled plasma (ICP-OES) is used inductively coupled plasma for forming excited atoms and ions that emit electromagnetic radiation at wavelengths that are characteristic of the individual elements. Advantages of ICP-OES are excellent detection limits and wide linear range, the low chemical interference, as well as a stable and repeatable signal. The biggest advantage of this technique is a multi-element analysis in a short period of time.