Online monitoring

S. Motlagh and J. Pawliszyn, Online monitoring of flowing samples using solid phase mia oextraaion-gas chr-omatography . Anal. Chim. Acta. 284 265-273 (1993). 

S. Sayler, Optical biosensor for environmental online monitoring of naphthalene and salicylate bioavailability with an immobilized biolumine.scent catabolic reporter bacterium. Appl. Environ. Microbiol. 60 1494 (1994). 

Aurora Biomolecules dedicates to peptide synthesis (and polyclonal antibody production) for any small quantity purpose. FMOC chemistry (on Perceptive Biosystems Pioneer instruments) is used for peptides synthesis Online monitoring of the coupling efficiencies and HATU activation helps insure that the major component of the synthesis is the correct oligopeptide. Purification is firstly carried out by size exclusion chromatography, and then by HPLC on a PE vision purification workstation. Typically, 20 mg of pure peptide are obtained. The molecular weight of the purified peptide is determined as a final confirmation of quality. 

E. Zilkha, T.P. Obrenovitch, A. Koshy, H. Kusakabe, and H.P. Bennetto, Extracellular glutamate online monitoring using microdialysis coupled to enzyme-amperometric analysis. J. Neurosci. Methods. 60,1-9 (1995). 

The use of sensors and biosensors on a continuous real-time measurements (online monitoring systems), at increasingly more and more affordable costs, introduces new possibilities on monitoring that cannot be underestimated. In turn, those new technologies generate new problems, mostly related to the amount of results available and their interpretation. 

Many of the characterization techniques described in this chapter require ambient or vacuum conditions, which may or may not be translatable to operational conditions. In situ or in opemndo characterization avoids such issues and can provide insight and information under more realistic conditions. Such approaches are becoming more common in X-ray adsorption spectroscopy (XAS) methods ofXANES and EXAFS, in NMR and in transmission electron microscopy where environmental instruments and cells are becoming common. In situ MAS NMR has been used to characterize reaction intermediates, organic deposits, surface complexes and the nature of transition state and reaction pathways. The formation of alkoxy species on zeolites upon adsorption of olefins or alcohols have been observed by C in situ and ex situ NMR [253]. Sensitivity enhancement techniques play an important role in the progress of this area. In operando infrared and RAMAN is becoming more widely used. In situ RAMAN spectroscopy has been used to online monitor synthesis of zeolites in pressurized reactors [254]. Such techniques will become commonplace. 

W. Shen, X. Chen, Online monitoring of kappa number during batch pnlping by visible spectroscopy, Ind. Eng. 

J. Monni, R Niemela, L. Alvila and T.T. Rakkanen, Online monitoring of synthesis and curing of phenol-formaldehyde resol resins by Raman spectroscopy. Polymer, 49, 3865-3874 (2008). 

S. Sekulic, J. Wakeman, P. Doherty and P. Hailey, Automated system for the online monitoring of powder blending processes using near-infrared spectroscopy. Part II Qualitative approaches to blend evaluation, J. Pharm. Biomed. Anal, 17, 1285-1309 (1998). 

Installation of online monitoring systems at appropriate locations and controlled dosing of bleach chemicals can aid in the reduction of chlorinated organics in effluents. 

Hoogenboom R, Fijten MWM, Abeln CH, Schubert US (2004) High-throughput investigation of polymerization kinetics by online monitoring of GPC and GC. Macromol Rapid Commun 25 237-242... 

Fig. 4. Principle of function of the field device for online monitoring of inhibitors in sewage systems...

Lindinger, W., Hansel, A., Jordan, A. (1998) Online monitoring ofvolatile organic compounds at pptv levels by means of proton-transfer-reaction mass spectrometry (PTR-MS). Medical applications, food control and environmental research. Int. J. Mass Spectrom. Ion Processes 173 191-241. 

Zimmermann, R., Heger, H.J., Yeretzian, C., Nagel, H., Boesl, U. (1996) Application of laser ionization mass spectrometry for online monitoring of volatiles in the headspace of food products roasting and brewing of coffee. Rapid Commun. Mass Spectrom. 10 1975-1979. 

The major difficulty in analyzing OPPs in fatty samples has to do with the wide polarity range for both pesticides and lipids present in the matrix. Normal-phase HPLC is an adequate technique for cleaning up this type of sample using silica gel and modifiers with different polarity. In fact, an automated sample-cleanup system based on normal-phase HPLC using a silica gel column has been reported efficiently to clean up and fractionate chlorpyriphos, chlorpyriphos methyl, and their metabolites in molluscs. The system presents several advantages The procedure is fully automated, from the injection of the extract to the collection of fractions, which are injected directly into the GC system, and a diode array detector (DAD) allows online monitoring of the elution of lipids (68). 

For gas-phase sensors, both remarkable selectivity and very low LOD are important. Sensors featuring MIP recognition combined with SAW transduction can meet these requirements. The MIP-PZ chemosensors operating in gases are devised for two main applications, namely for indoor gas inspection and online monitoring of volatile organic compounds. The latter is essential to protect humans from threats of environmental atmospheric pollutants. 

McCaffery, T.R. 8c Durant, Y.G. Application of Low-Resolution Raman Spectroscopy to Online Monitoring of Miniemulsion Polymerization /. Appl. Polym. Sci. 2002, 86, 1507-1515. 

Cimander, C. Mandenius, C.-F., Online monitoring of a bioprocess based on a multi-analyser system and multivariate statistical process modelling /. Chem. Technol. Biotechnol. 2002, 77, 1157-1168. 

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