Table of Contents
What is solid phase microextraction used for?
SPME is widely used for a variety of applications involving environmental, biological and pharmaceutical samples, foods and beverages, flavors and fragrances, forensics and toxicology and product testing. Typical uses include: Environmental analyses of water & air samples.
What is solid phase microextraction sampling?
SPME is a sampling technique based on absorption developed by Arthur and Pawliszyn. With SPME, the analytes are absorbed from the liquid or gaseous sample on to an absorbent coated fused silica fibre, which is part of the syringe needle, for a fixed time.
What is headspace solid phase microextraction?
Headspace solid-phase microextraction (HS-PME) is a technique which is used to prepare samples. This technique does not require the use of solvents, therefore it is suitable for preparing samples that are volatile, such as benzene, ethylbenzene, toluene and xylenes.
What is liquid-phase microextraction?
Liquid-phase microextraction is a miniaturized form of traditional liquid–liquid extraction in which the extracting organic phase is limited to a few microliters for extraction of target analytes.
What is the advantage of performing dynamic LPME?
Dynamic LPME This technique can be used for both SDME and HF-LPME. Dynamic LPME improves extraction rate compared with static solvent microextraction but the apparatus can be more complex.
What is a dispersive solvent?
Abstract. Dispersive liquid-liquid microextraction (DLLME) is an extraction technique developed within the last decade, which involves the dispersion of fine droplets of extraction solvent in an aqueous sample.
What is enrichment factor in analytical chemistry?
The enrichment factor (EF) was defined as the ratio of the analyte concentration in the collected phase to the analyte concentration in the aqueous sample where the analyte concentration in the collected phase was calculated from the direct calibration graph (0.2–10 µg mL−1) of parabens in acetonitrile.
What is headspace in a vial?
Phases of the Headspace Vial The gas phase is commonly referred to as the headspace and lies above the condensed sample phase. S = the sample phase. The sample phase contains the compound(s) of interest. It is usually in the form of a liquid or solid in combination with a dilution solvent or a matrix modifier.
What is enrichment factor in extraction?
The enrichment factor (EF) was used to evaluate the extraction efficiency under different conditions. The EF was defined as the ratio between the analyte concentration in the settled phase (Csed) and the initial concentration of the analyte (C0) in the urine sample.
How do you calculate enrichment factor?
EF for each metal can be calculated by finding the average concentration of a metal in a particular area and dividing it than by the background level of the same metal. The background values of heavy metals can be determine from the total metal contents in the surface horizons(topsoil) and are given as 90th percentile.
What is the most widely used method is used to extract accelerant from fire debris?
Gas chromatography-mass spectrometry is the most widely used analytical technique for the determination of accelerants in fire debris.
What is direct immersion?
The second method is direct immersion (DI-SPME), in which the fiber is directly immersed in a small volume of the liquid-extracted sample [5,6,7].
What is headspace in packaging?
The inside (volume) of packaging that is not occupied by the product itself is referred to as headspace. The atmosphere within this space is referred to as the headspace gas, and is analysed by measuring the volume and proportion of these residual gases (O2, CO2, N2, etc.) within packages.
What is MEPs (packed sorbent microextraction)?
In the past decade, microextraction by packed sorbent (MEPS) was introduced as a simple, fast, on-line sample-preparation technique. Also, MEPS requires less sample and less solvent.
How much sorbent is in a MEPs syringe?
In MEPS, ~2 mg of the solid-packing sorbent is packed inside a syringe (100–250 µL) as a plug or between the barrel and the needle as a cartridge, as shown in Fig. 1. Sample extraction and enrichment can be accomplished on the packed sorbent.
How to do sample extraction and enrichment with packed sorbent?
Sample extraction and enrichment can be accomplished on the packed sorbent. This technique combines sample extraction, pre-concentration and clean-up in a single device composed of the following two parts: the MEPS syringe and the MEPS cartridge, also known as the BIN.
What is MEPs used for in MS?
As a flexible sample-preparation method, MEPS can be used for direct connection to MS and a few works have been published with this approach. MEPS was directly connected to a TOF mass spectrometer and used for detection of drugs of abuse in human-urine samples [14].