Analyte derivatization solid-phase microextraction

Sarrion, M.N. Santos, F.J. and Galceran, M.T. In situ derivatization/solid-phase microextraction for the determination of haloacetic acids in water. Analytical Chemistry 2000, 72 (20), 4865 873. 

Derivatization/solid-phase microextraction New approach to polar analytes, J. Anal. Chem., 69, 196-205. 

Nishida M, Yashiki M, Namera A, Kimura K (2006) Single hair analysis of methamphetamine and amphetamine by solid phase microextraction coupled with in matrix derivatization. J ChromatogrB Analyt TechnolBiomedLifeSci 842(2) 106-110. doi S 1570-0232(06)00580-0 [pii] 10.1016/j. j chromb.2006.07.039... 

The most sensitive method for CVAA has recently been reported by Wooten et al. (39) using solid-phase microextraction to concentrate the derivatized analyte. Urine, with added ammonium acetate buffer and PhAsO as an internal standard, was derivatized directly with 1,3-propanedithiol and the derivative concentrated on a poly(dimethylsiloxane) (PDMS) solid-phase microextraction (SPME) fiber. Analysis was by automated GC/MS using SIM of the isotopic MH+ ions. An impressive detection limit of 7.4pg/ml was reported, using a benchtop GC/MS system. The method was validated using spiked human urine. 

Analytical quantification of BAs may be difficult due to the complexity of some food matrices and the low concentrations of BAs generally encountered in the majority of foodstuffs. In addition, the low volatility of these compounds and the lack of chromophores for most of the BAs, does not allow the rapid direct detection by ultraviolet and visible (UV and vis) spectrometric or fluorimetric (FL) methods. In general, in order to obtain an optimal analysis, extraction, clean-up, concentration, and derivat-ization procedures are required. Extraction methods usually based on liquid-liquid or solid-phase extraction with C18 or ion-exchange cartridges can be applied to improve selectivity and sensitivity (Giannotti et al., 2008 Pena-Gallego, Hemdndez-Orte, Cacho, Ferreira, 2009). Alternative approaches, such as solid-phase microextraction... 

Jurado C, Gimenez MP, Soriano T, Menendez M, and Repetto M (2000) Rapid analysis of amphetamine, methamphetamine, MDA, and MDMA in urine using solid-phase microextraction, direct on-fiber derivatization, and analysis by GC-MS. Journal of Analytical Toxicology 24(1) 11-16. 

See also Atomic Absorption Spectrometry Principles and Instrumentation. Atomic Emission Spectrometry Inductively Coupled Plasma. Cosmetics and Toiletries. Derivatization of Analytes. Electrophoresis Is-otachophoresls. Environmental Analysis. Enzymes Overview. Extraction Supercritical Fluid Extraction Solid-Phase Extraction Solid-Phase Microextraction. Ion Exchange Ion Chromatography Applications. Liquid Chromatography Reversed Phase Liquid Chromatography-Mass Spectrometry. Nuclear Magnetic Resonance Spectroscopy - Applicable Elements Carbon-13 Phosphorus-31. Perfumes. 

Solid phase microextraction (SPME) involves extraction onto a thin fiber and the technique has become more prevalent recently and additionally provides a preconcentration of analytes prior to analysis. The fibers used in the technique can be coated with a range of stationary phases and a nonpolar phase such as polydimethylsiloxane (PDMS) is typically used for the extraction of derivatized organotin species. An equilibrium is established between the sample extract solution (or the headspace above the solution) and the stationary phase coating the fiber. The analytes are then typically desorbed from the fiber for analysis, for example, using thermal desorption during GC analysis. The technique allows rapid and solvent-free extraction of the analytes. Very good extraction has been achieved for water samples however, the technique has been shown to be more variable with more complex matrices. 

See also Atomic Absorption Spectrometry Interferences and Background Correction. Atomic Emission Spectrometry Principles and Instrumentation Interferences and Background Correction Flame Photometry Inductively Coupled Plasma Microwave-Induced Plasma. Atomic Mass Spectrometry Inductively Coupled Plasma Laser Microprobe. Countercurrent Chromatography Solvent Extraction with a Helical Column. Derivatization of Analytes. Elemental Speciation Overview Practicalities and Instrumentation. Extraction Solvent Extraction Principles Solvent Extraction Multistage Countercurrent Distribution Microwave-Assisted Solvent Extraction Pressurized Fluid Extraction Solid-Phase Extraction Solid-Phase Microextraction. Gas Chromatography Ovenriew. Isotope Dilution Analysis. Liquid Chromatography Ovenriew. 

The solid-phase microextraction fiber was introduced into the port of a gas chromatograph held at 280 C for 4 min to desorb derivatized analytes from the fiber onto a chromatography column held at 80°C. Analytes have negligible vapor pressure at 80 C, so they remain at the start of the column until the column temperature is raised. 

Martos, P.A. and Pawlisz)m, J. Sampling and derivatization of formaldehyde using solid-phase microextraction with on-fiber derivatization. Analytical Chemistry 1998, 70 (11), 2311-2320. 

When coupling gas chromatography to plasma spectrometry, the use of solid-phase microextraction (SPME) as a solvent-free extraction tool is particularly useful. Indeed, volatile species (directly or following derivatization) can be collected from either the sample headspace or the liquid phase, and non-volatile species from the liquid phase even flash-heating can be used for rapid transfer of the analytes into the GC [721]. Multi-capillary GC can also be used for high throughput [722]. 

Insofar as the derivatization can be considered one of the stages of sample preparation for chromatographic analysis, it can be combined with other procedures, for instance, the preconcentration of traces of analytes. For example, the yield of solid-phase extraction or microextraction of organic compounds from aqueous solutions with modified silica gels is better for more hydrophobic substances the preliminary conversion of acidic compounds into suitable derivatives is recommended. ... 

Different sample pretreatment operations include dilution, membrane-extraction (gas diffusion, dialysis), liquid-phase extraction techniques (liquid/liquid extraction, liquid-phase microextraction, single-drop microextraction) and solid reactors and packed columns aiming to facilitate online chemical derivatization, chromatographic separation of target species, removal of interfering matrix compounds, enzymatic assays, or determination of trace levels of analyte via sorptive preconcentration procedures (Marshall et al., 2003 Economou, 2005 Miro and Hansen, 2006 Theodoridis et al., 2007 McKelvie, 2008 Ruzicka, 2014). In this context, BIA and the LOV configurations are particularly useful. Acid-base titrations can also be automated using simple SIA manifolds and potentiometric (van Staden et al., 2002) or photometric (Kozak et al., 2011) detection. Typically, a zone of the sample to be titrated is sandwiched between two zones of titrant by aspiration. In the case of photometric detection, an additional zone of a suitable pH-sensitive colored indicator is aspirated. The stacked zones are delivered to the detector and the width of the peaks is monitored and related to the pH of the solution. 

---