Solid-phase microextraction liquids

C. Blasco, G. Font, J. Manes, Y. Pico, Solid-phase microextraction liquid chromatog-raphy/tandem mass spectrometry to determine postharvest fungicides in fmits. Anal. Chem. 75 (2003) 3606-3615. 

Alves C, Santos-Neto AJ, Fernandes C et al (2007) Analysis of tricyclic antidepressant drugs in plasma by means of solid-phase microextraction-liquid chromatography-mass spectrometry. J Mass Spectrom 42 1342-1347... 

Kataoka, H. and Pawliszyn, J., Development of in-tube solid-phase microextraction/liquid chromatography/electrospray ionization mass spectrometry for the analysis of mutagenic heterocyclic amines, Chromatographia, 50(9/10), 532-538, 1999. 

Kureckova, K., Maralikova, B., and Ventura, K., Supercritical fluid extraction of steroids from biological samples and first experience with solid-phase microextraction-liquid chromatography, Journal of Chromatography B—Analytical Technologies in the Biomedical and Life Sciences, 770, 83-89, 2002. 

Kelly, M.T. and Larroque, M., Trace determination of diethylphthalate in aqueous media by solid-phase microextraction-liquid chromatography. Journal of Chromatography A, 841,177,1999. 

In recent decades the development of preconcentration steps to be implemented prior to analytical determinations of trace level compounds has been explored in considerable depth. With a view to eliminating or at least minimising the use of organic solvents used in conventional liquid-liquid extraction, other methodologies have been developed, such as membrane extraction, solid-phase extraction, solid-phase microextraction, etc. 

SOLID-PHASE MICROEXTRACTION COUPLED WITH GAS OR LIQUID CHROMATOGRAPHY... 

S. Ulrich and J. Maitens, Solid-phase microextraction with capillai y gas-liquid cliro-matography and niti ogen-phosphoi us selective detection foi the assay of antidepressant drugs in human plasma , J. Chromatogr. B 696 217-234 (1997). 

A recent method, still in development, for determining total 4-nitrophenol in the urine of persons exposed to methyl parathion is based on solid phase microextraction (SPME) and GC/MS previously, the method has been used in the analysis of food and environmental samples (Guidotti et al. 1999). The method uses a solid phase microextraction fiber, is inserted into the urine sample that has been hydrolyzed with HCl at 50° C prior to mixing with distilled water and NaCl and then stirred (1,000 rpm). The fiber is left in the liquid for 30 minutes until a partitioning equilibrium is achieved, and then placed into the GC injector port to desorb. The method shows promise for use in determining exposures at low doses, as it is very sensitive. There is a need for additional development of this method, as the measurement of acetylcholinesterase, the enzyme inhibited by exposure to organophosphates such as methyl parathion, is not an effective indicator of low-dose exposures. 

The most widely employed techniques for the extraction of water samples for triazine compounds include liquid-liquid extraction (LLE), solid-phase extraction (SPE), and liquid-solid extraction (LSE). Although most reports involving SPE are off-line procedures, there is increasing interest and subsequently increasing numbers of reports regarding on-line SPE, the goal of which is to improve overall productivity and safety. To a lesser extent, solid-phase microextraction (SPME), supercritical fluid extraction (SEE), semi-permeable membrane device (SPMD), and molecularly imprinted polymer (MIP) techniques have been reported. 

The need to understand the fate of pesticides in the environment has necessitated the development of analytical methods for the determination of residues in environmental media. Adoption of methods utilizing instrumentation such as gas chro-matography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), liquid chromatography/tandem mass spectrometry (LC/MS/MS), or enzyme-linked immunosorbent assay (ELISA) has allowed the detection of minute amounts of pesticides and their degradation products in environmental samples. Sample preparation techniques such as solid-phase extraction (SPE), accelerated solvent extraction (ASE), or solid-phase microextraction (SPME) have also been important in the development of more reliable and sensitive analytical methods. 

During the last few years, miniaturization has become a dominant trend in the analysis of low-level contaminants in food and environmental samples. This has resulted in a significant reduction in the volume of hazardous and expensive solvents. Typical examples of miniaturization in sample preparation techniques are micro liquid/liquid extractions (in-vial) and solvent-free techniques such as solid-phase microextraction (SPME). Combined with state-of-the-art analytical instrumentation, this trend has resulted in faster analyses, higher sample throughputs and lower solvent consumption, whilst maintaining or even increasing assay sensitivity. 

Diffusive sampler Membrane extraction (MESI) Liquid-liquid extraction (LLE) Solid-phase extraction (SPE) SPE-PTV-GC Solid-phase microextraction (SPME) Headspace GC (SHS, DHS) Large-volume injection (LVI) Coupled HPLC-GC Membrane extraction (MESI) Difficult matrix introduction (DMI) Conventional solvent extraction methods 1 Pressurised solvent extraction methods Headspace GC (SHS, DHS) Thermal desorption (TD, DTD) Pyrolysis (Py) Photolysis Photon extraction (LD) Difficult matrix introduction (DMI)... 

Miniaturisation of scientific instruments, following on from size reduction of electronic devices, has recently been hyped up in analytical chemistry (Tables 10.19 and 10.20). Typical examples of miniaturisation in sample preparation techniques are micro liquid-liquid extraction (in-vial extraction), ambient static headspace and disc cartridge SPE, solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE). A main driving force for miniaturisation is the possibility to use MS detection. Also, standard laboratory instrumentation such as GC, HPLC [88] and MS is being miniaturised. Miniaturisation of the LC system is compulsory, because the pressure to decrease solvent usage continues. Quite obviously, compact detectors, such as ECD, LIF, UV (and preferably also MS), are welcome. 

Moder M, Popp P, Eisert R, Pawliszyn J. Determination of polar pesticides in soil by solid phase microextraction coupled to high-performance liquid chromatography-electrospray/mass spectrometry. Fresenius. J. Anal. Chem. 1999 363 680-685. 

Isotope fractionation between the vapor phase and the dissolved aqueous phase has been studied only for toluene and trichloroethylene (carbon only [545, 690]). Fractionation associated with adsorption has been quantified only for toluene in regard to sample extraction using a poly(dimethylsilo-xane)-coated solid-phase microextraction fiber [373] and qualified for benzene, toluene, and ethylbenzene based on high-pressure liquid chromatography analyses of isotopically labeled and unlabeled compounds (carbon and hydrogen [692]). Isotope fractionation associated with the reductive dechlorination of chlorinated ethylenes by zero-valent iron and zinc has been... 

In 2003, Smith reviewed newer sample preparation techniques, including pressurized liquid extraction, solid phase microextractions, membrane extraction, and headspace analysis. Most of these techniques aim to reduce the amount of sample and solvent required for efficient extraction. 

Air, water Solid phase microextraction (from air, water, or headspace over water) GC/ECD 0.9 ppb (v/v) gas phase 30 ng/L (30 ppt, w/v) liquid phase No data Chai et al. 1993... 

Experiments to identify disinfection by-products (DBFs) have been carried out using two different procedures. In the first, natural waters (e.g., river, lake) are reacted with the disinfectant, either in a pilot plant, an actual treatment plant, or in a controlled laboratory smdy. fii the second type of procedure, aquatic humic material is isolated and reacted with the disinfectant in purified water in a controlled laboratory study. This latter type of study is relevant because humic material is an important precursor of THMs and other DBFs. Aquatic humic material is present in nearly all natural waters, and isolated humic material reacts with disinfectants to produce most of the same DBFs found from natural waters. Because DBFs are typically formed at low levels (ng/L-pg/L), samples are usually concentrated to allow for DBF detection. Concentration methods that are commonly used include solid phase extraction (SFE), solid phase microextraction (SFME), liquid-liquid extraction, and XAD resin extraction (for larger quantities of water) [9]. 

Sampling of these substances has been carried out following three approaches liquid absorbents [47], solid-phase microextraction (SPME) fibres [43] and filter substrates (mostly quartz fibre filters but also PTFE membranes [1, 42, 48, 49]). When filter substrates are used, atmospheric particles are collected over 24-h periods using high-volume (dichotomous or single-filter instruments [1, 48]), medium-volume or low-volume samplers (operated to ensure collection of sufficient aerosol mass [37, 50]). Samples were always stored at low temperamres (refrigerated or frozen) to ensure sample preservation. 

Excerpt 4C is taken from an article in Analytical Chemistry. Headspace solid-phase microextraction (HSSPME) is coupled with GC to quantify polychlorinated biphenyls (RGBs) in milk. The RGBs are volatilized out of the liquid phase (milk) into the gas phase (headspace) and concentrated on an SPME fiber. The concentrated RGBs on the fiber are then injected into the GG. 

Satterfield, M., Black, D.M., and Brodbelt, J.S., Detection of the isoflavone aglycones genistein and daidzein in urine using solid-phase microextraction-high-performance liquid chromatography-electrospray ionization mass spectrometry, J. Chromatogr. B, 759, 33, 2001. 

Aresta A, Palmisano F, Vatinno R, Zambonin CG (2006) Ochratoxin A Determination in Beer by Solid-Phase Microextraction Coupled to Liquid Chromatography with Florescence Detection A Fast and Sensitive Method for Assessment of Noncompliance to Legal Limits. J Agric Food Chem 54 1594... 

Yang et al. [47,48,53,54] developed a HWG sensing system for liquid and soil analyses based on an extractive polymer membrane coated onto the inside of the HWG. The polymer coating performs a solid-phase microextraction of the analyte from the headspace of the sample and preconcentrates the analyte prior to IR analysis. 

Among the numerous techniques for separating and enriching organic compounds from water samples, the following are worthy of mention solid-phase extraction (SPE), solid-phase microextraction (SPME), liquid-liquid extraction (LLE), and lyophilization. 

Popp, P., C. Bauer, M. Moder, and A. Paschke. 2000. Determination of polycyclic aromatic hydrocarbons in waste water by off-line coupling of solid-phase microextraction with column liquid chromatography. J. Chromatogr. A 897 153-159. 

Negrao, M.R. and M.F. Alpendurada. 1998. Solvent-free method for the determination of polynuclear aromatic hydrocarbons in waste water by solid-phase microextraction-high-performance liquid chromatography with photodiode-array detection. J. Chromatogr. A 823 211-218. 

Zambonin, C.G. 2003. Coupling solid-phase microextraction to liquid chromatography. A review. Anal. Bioanal. Chem. 375 73-80. 

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