Solid-phase extraction online

A recent method [ 114] for the speciation of organotin compounds in seawater combines solid-phase extraction, online HG, and GC with MIAE. This method enjoys a 0.5 pg detection limit for tin. 

Another advanced and novel sample preparation technique is online solid phase extraction (online SPE). Although the extraction mechanism is as the same as traditional offline SPE, online SPE offers several advantages. Because sample preparation is carried out during analysis, it eliminates the time needed for sample preparation thus increases throughput significantly. Additionally, because the entire sample is eluted to the LC-MS/MS system, it may increase assay sensitivity. Finally, because there is no manual extraction involved, it may reduce human error, potential contamination, and inconsistent recovery. 

D. BaiTon, J. Barbosa, J. A. Pascual and J. Segura, Dkect deteimination of anabolic steroids in human urine by online solid-phase extraction/liquid cliromatography/mass specti ometi y , 7. Mass Spectrom. 31 309-319 (1996). 

Development and validation of protocols for solid-phase extraction coupled to LC and LC-MS have been described [136]. Hennion [137] has reviewed online SPE-HPLC coupling followed by various detection modes. 

Lopez-Sema R, Perez S, Ginebreda A, Petrovic M, Barcelo D (2010) Fully automated determination of 74 pharmaceuticals in environmental and waste waters by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry. Talanta 83(2) 410 124... 

Pocurull et al. [130] used the online solid-phase extraction GCMS preconcentration method to determine organotin antifouling compounds in seawater 10 ng/1 detection limits were achieved using a 10 ml sample. 

Ferrer and Barcelo [131] used online solid-phase-liquid chromatography mass spectrometry for the simultanous determination of organotin antifouling herbicides in marine water. The solid-phase extraction was carried out on polymeric cartridges after percolation of 100 ml of the seawater sample, and... 

Aguilar C, Ferrer I, Borrull F, Marce RM, Barcelo D (1999) Monitoring of pesticides in river water based on samples previously stored in polymeric cartridges followed by online solid-phase extraction-liquid chromatography-diode array detection and confirmation by atmospheric pressure chemical ionization mass spectrometry. Anal Chim Acta 386 (3) 237-248... 

Analysis of pesticides in water was performed by fully automated online solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/ MS) [25, 31]. These pesticides (a total of 22 belonging to the classes of triazines, OP, chloroacetanilides, phenylureas, thiocarbamates, acid herbicides, and anilides) were selected on the basis of previously published studies [20, 25], information gathered from the water authorities, and known use in rice crops. 

Kampioti AA, da Cunha ACB, de Alda ML et al (2005) Fully automated multianalyte determination of different classes of pesticides, at picogram per litre levels in water, by online solid-phase extraction-liquid chromatography-electrospray-tandem mass spectrometry. Anal Bioanal Chem 382 1815-1825... 

Online Solid Phase Extraction as Tool for High-Throughput... 

This chapter will review recent advances in mass spectrometry, liquid chromatography, and sample preparation techniques that aim at achieving high throughput. In particular, online solid phase extraction and multiplexed HPLC front ends for quantitative bioanalysis will be discussed in detail. 

Sample preparation—Analytes of interest were extracted from human plasma using the online solid phase extraction technique. The steps required are noted below ... 

In our laboratories, a cycle time of 90 sec can be achieved with a dilution factor of 1 25 for a given sample concentration, allowing the purity and identity control of two and a half 384-well microtiter plates per day. The online dilution eliminated an external step in the workflow and reduced the risks of decomposition of samples in the solvent mixture (weakly acidic aqueous solvent) required for analysis. Mao et al.23 described an example in which parallel sample preparation reduced steps in the workflow. They described a 2-min cycle time for the analysis of nefazodone and its metabolites for pharmacokinetic studies. The cycle time included complete solid phase extraction of neat samples, chromatographic separation, and LC/MS/MS analysis. The method was fully validated and proved rugged for high-throughput analysis of more than 5000 human plasma samples. Many papers published about this topic describe different methods of sample preparation. Hyotylainen24 has written a recent review. 

Typical instrument set-ups for online sample preparation, for example, solid phase extraction and sample pre-concentration, require the control of a six-port valve with an additional special column and a second pump. Ideally, this system will be fully controlled by the data acquisition software (Figure 3.12 (A)). 

Solid phase extraction (SPE) is fast and can work as a clean-up method when combined with capillary electrophoresis or used prior to HPLC/MS.34-37 Kerns et al.35 described an online alternating parallel SPE column with MS/MS detection and a turn-around time of 1.1 min. 

Online Solid Phase Extraction LC/MS/MS for High-Throughput Bioanalytical Analysis... 

Asperger A. et al., 2002. Trace determination of priority pesticide in water by means of high-speed online solid-phase extraction-liquid chromatography-tandem mass spectrometry using turbulent-flow chromatography columns for enrichment and a short monolithic column for fast liquid chromatographic separation. J Chromatogr A 960 109. 

Bourgogne E., Grivet C., and Hopfgartner G., 2005. Determination of talinolol in human plasma using automated online solid phase extraction combined with atmospheric pressure chemical ionization tandem mass spectrometry. J Chromatogr B 820 103. 

Chao M. et al., 2005. Rapid and sensitive quantification of urinary N7-mthelguanine by isotope-dilution liquid chromatography/electrospray ionization tandem mass spectrometry with online solid-phase extraction. Rapid Commun Mass Spectrom 19 2427. 

Ding J. and Neue U.D., 1999. A new approach to the effective preparation of plasma samples for rapid drug quantitation using online solid phase extraction mass spectrometry. Rapid Commun Mass Spectrom 13 2151. 

Ferrer I. and Barcelo, D., 1999. Simultaneous determination of antifouling herbicides in marina water samples by online solid-phase extraction followed by liquid chromatography-mass spectrometry. J Chromatogr A 854 197. 

Gon9alves J.C.S. et al., 2005. Online solid-phase extraction coupled with high-performance liquid chromatography and tandem mass spectrometry (SPE HPLC-MS-MS) for quantification of bromazepam in human plasma. Ther Drug Monit 27 601. 

Gundersen T.E. and Blomhoff R., 1999. Online solid-phase extraction and isocratic separation of retinoic acid isomers in microbore column switching system. Meth Enzymol 299 430. 

Hogenboom A.C., Niessen W.M.A., and Brinkman U.A., 1999a. Online solid-phase extraction-short-column liquid chromatography combined with various tandem mass spectrometric scanning strategies for the rapid study of transformation of pesticides in surface water. J Chromatogr A 841 33. 

Hogenboom A.C. et al., 1999b. Accurate mass determination for the confirmation and identification of organic microcontaminants in surface water using online solid-phase extraction liquid chromatography electrospray orthogonal-acceleration time-of-flightmass spectrometry. Rapid Commun Mass Spectrom 13 125. 

Kahlich R. et al., 2006. Quantitative determination of piritramide in human plasma and urine by off- and online solid-phase extraction hquid chromatography coupled to tandem mass spectrometry. Rapid Commun Mass Spectrom 20 275. 

Koal T. et al., 2004. Simultaneous determination of four immunosuppressant by means of high speed and robust online solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. J Chromatogr B 805 215. 

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