Reaction-product analyzer

Measurement of Reaction Products Impregnated paper-tape devices Photometric reaction product analyzers... 

M. Galloway and S.A. Soper, Contact conductivity detection of polymerase chain reaction products analyzed by reverse-phase ion pair microcapillary electrochromatography, Electrophoresis, 23 (2002) 3760-3768. M. Masar, M. Dankova, E. Olvecka, A. Stachurova, D. Kaniansky and B. Stanislawski, Determination of free sulfite in wine by zone electrophoresis with isotachophoresis sample pretreatment on a column-coupling chip, J. Chromatogr. A, 1026 (2004) 31-39. 

Studies of the behavior of Maillard reaction products analyzed by solid-phase microextraction (SPME) -GC/MS selective detection have been realized by Coleman (1996, 1997). A concerted procedure for the generation, concentration, fractionation, and sensory evaluation of Maillard reaction products has recently been published by Parliment (1999). 

Similarly, enzymatic reactions can be performed directly on a MALDI plate, quenched, and the reaction products analyzed [43]. Various laser desorption/ionization (LDI)-based techniques facilitate such off-line measurements [44,45]. When the operations of initiating and quenching the chemical reactions are carried out manually, the temporal resolution of the LDI-MS-based methods is typically in the order of a few minutes. However, by implementing flow mixing and quenching methodology, one can perform observations of sub-second phenomena with this kind of off-line MS detection (see, e.g., [46-48]). 

Coleman, W.M., A study of the behavior of Mafllard reaction products analyzed by solid-phase microextraction gas chromatography-mass selective detection, J. Chromatograph. Sci., 34, p. 213, 1996. 

Final state analysis is where dynamical methods of evolving states meet the concepts of stationary states. By their definition, final states are relatively long lived. Therefore experiment often selects a single stationary state or a statistical mixture of stationary states. Since END evolution includes the possibility of electronic excitations, we analyze reaction products in terms of rovibronic states. 

Polyester composition can be determined by hydrolytic depolymerization followed by gas chromatography (28) to analyze for monomers, comonomers, oligomers, and other components including side-reaction products (ie, DEG, vinyl groups, aldehydes), plasticizers, and finishes. Mass spectroscopy and infrared spectroscopy can provide valuable composition information, including end group analysis (47,101,102). X-ray fluorescence is commonly used to determine metals content of polymers, from sources including catalysts, delusterants, or tracer materials added for fiber identification purposes (28,102,103). 

When, in NRA, energy spectra of emitted particles are analyzed, a sufficiently thick foil in front of the detector is usually used to absorb the scattered projectiles. This reduces the depth resolution of NRA, because of energy loss straggling of the reaction products in the foil. 

Heating the white reaction product to 140 C for one hour in vacuum caused a visible iodine evolution and approximately 40% weight loss. No further weight loss was observed up to 250°C. The gaseous products from the pyrolysis were not collected. The green product from pyrolysis analyzed Pu, 43 3% I, 50 2% C, 4.9 1%. The empirical formula PuI2C2H3 has the calculated composition Pu, 45.88% I, 48.75% C, 4.79%. 

The ions A move in mass spectrometer A in a vertical plane and then cross the collision chamber. The reaction products (ithe ions B) are extracted from the collision chamber at right angles to the direction of the ion beam A and are analyzed by mass spectrometer B, which is placed in a horizontal plane. 

Investigating Ion-Molecule Reactions by Analyzing Neutral Products Formed in the Radiolysis and Photoionization of Hydrocarbons... 

Initial work was carried out with 3,9-bis(methylene-2,4,8,10-tetraoxaspiro[5,5] undecane) where R = H (11). However, this monomer contains two electron donor alkoxy groups on one double bond which is thus highly susceptible to a cationic polymerization. For this reason, the monomer is extremely difficult to handle and cannot be analyzed by gas chromatography since it does not survive passage through the column. It is prepared by the dehydrohalogen-ation reaction of the reaction product of pentaerythritol and chloro-acetaldehyde,... 

Some chemical modification studies on the sea anemone toxins have unfortunately been less than rigorous in analyzing the reaction products. Consequently, results from many of these studies can only provide suggestions, rather than firm conclusions, regarding the importance of particular sidechains. Many such studies also have failed to determine if the secondary and tertiary structures of the toxin products were affected by chemical modification. 

Our first step is to analyze the solid state reaction by means of the values determined in the TGA analysis run.The reaction products are given above, along with the requisite molecular weights. 

Gas-phase reactions have been carried out in 160 mL quartz vessels, and the products analyzed online by mass spectrometry (Brubaker and Hites 1998). Hydroxyl radicals were produced by photolysis of ozone in the presence of water ... 

Reaction products were analyzed by on-line gas chromatography with a Shimadzu GC-14A gas chromatograph equipped with a 50 m CP Sil-5 fused silica capfllary column and a flame ionization detector. Reaction intermediates were identified by GC-MS. Samples were taken after 50 h on stream when the activity of the catalyst was stable, with n-nonane and n-dodecane as internal standards. Space time was defined as t = e Voat/vgas, where e is the void fraction of the... 

Catalytic reactions. The reaction was carried out at 543-643 K by using a flow reaction system with a mixtiue of EA, NH3, and Nz in the ratio of 1/50/25 at atmospheric pressure. The flow rate of the mixture gas was 76 cm min. Prior to the reaction, the catalyst was calcined at 773 K under O2 flow for 2 h. The reaction products were analyzed by an on-line gas chromatograph (FID) which was equipped with a 30-m capillary column (TCI701). 

The catalyst prepared above was characterized by X-ray diffraction, X-ray photoelectron and Mdssbauer spectroscopic studies. The catalytic activities were evaluated under atmospheric pressure using a conventional gas-flow system with a fixed-bed quartz reactor. The details of the reaction procedure were described elsewhere [13]. The reaction products were analyzed by an on-line gas chromatography. The mass balances for oxygen and carbon beb een the reactants and the products were checked and both were better than 95%. 

P 38] Ethanol solutions of ethyl propiolate and diisopropylethylamine were pumped via electroosmotic flow through the micro channels of the reactor [8], By mixing thereof the enolate was obtained. By subsequent contacting with the 1,3-dicarbonyl compound, the product was obtained. The temperature was set to room temperature. In a period of 20 min a volume sufficiently large for analysis was sampled. The reaction product spectra was analyzed by GC/MS via comparison with synthetic standards. The remaining amount of diketone was used for calculating conversions. 

In a typical run, bis(l,2-diphenylphosphino)ethane (DPPE) (0.022 g, 0.05 mmol) and 1,3 diene (32.5 mmol) are added to a portion of the co-condensate, containing 5.2 mg of rhodium (0.05 mg. atom) in 10 ml of mesitylene. The solution is introduced by suction into an evacuated, 80 ml stainless steel autoclave. Carbon monoxide is introduced to the desired pressure and the autoclave is rocked and heated at 80 °C. Hydrogen is rapidly charged to give 1 1 gas composition. When the pressure reaches the theoretical value corresponding to the desired conversion, the autoclave is cooled, depressurised, and the reaction mixture analyzed by GLC. The crude product is distilled. The aldehydes are obtained as pure samples by preparative GLC and characterized by H NMR spectroscopy and GC-MS analysis. 

Product analysis Reaction mixtures were analyzed by GC using a crosslinked 5% phenyl methyl silicone (HP5, 30 m) or a nonbonded, poly(80% biscyanopropyl/20% cyanopropylphenyl siloxane SP2330, 60 m) capillary colunm. Reaction products were identified through their MS (HP 5971 series) and H NMR spectra (Bruker 300... 

It appeared that, we needed to limit or omit the ethyl iodide if we were going to operate the ethylene carbonylation in ionic liquids. Unfortunately, the previous literature indicated that EtI or HI (which are interconvertible) represented a critical catalyst component. Therefore, it was surprising when we found that, in iodide based ionic liquids, the Rh catalyzed carbonylation of ethylene to propionic acid was still operable at acceptable rates in the absence of ethyl iodide, as shown in Table 37.2. Further, we not only achieved acceptable rates when omitting the ethyl iodide, we also achieved the desired reduction in the levels of ethyl propionate. More importantly, when the reaction products were analyzed, there was no detectable ethyl iodide formed in situ. However, we should note that we now observed traces of ethanol which were normally undetectable in the earlier Ed containing experiments. 

Hydrolytic Kinetic Resolution (HKR) of epichlorohydrin. The HKR reaction was performed by the standard procedure as reported by us earlier (17, 22). After the completion of the HKR reaction, all of the reaction products were removed by evacuation (epoxide was removed at room temperature ( 300 K) and diol was removed at a temperature of 323-329 K). The recovered catalyst was then recycled up to three times in the HKR reaction. For flow experiments, a mixture of racemic epichlorohydrin (600 mmol), water (0.7 eq., 7.56 ml) and chlorobenzene (7.2 ml) in isopropyl alcohol (600 mmol) as the co-solvent was pumped across a 12 cm long stainless steel fixed bed reactor containing SBA-15 Co-OAc salen catalyst (B) bed ( 297 mg) via syringe pump at a flow rate of 35 p,l/min. Approximately 10 cm of the reactor inlet was filled with glass beads and a 2 pm stainless steel frit was installed at the outlet of the reactor. Reaction products were analyzed by gas chromatography using ChiralDex GTA capillary column and an FID detector. 

The products were identified by comparing the retention times of the reaction products with commercial compounds, and by GC-MS analysis in a Hewlett-Packard 5973/6890 GC equipped with an electron impact ionization at 70 eV detector and a cross-linked 5% PH ME siloxane (0.25 mm coating) capillary column. The reaction products were separated from the catalyst with filter syringes and analyzed in an Agilent 4890D and a Varian 3400 GC equipped with a flame ionization detector, and CP-Sil 8CB (30 m x 0.53 mm x 1.5 pm) and DB-1 (50 m x 0.52 mm x 1.2 pm) columns, respectively. Decane was used as an internal standard. The catalyst was thoroughly washed after reaction with acetonitrile, acetone and water, and dried overnight under vacuum at 40°C. 

Online detection using 4H nuclear magnetic resonance (NMR) is a detection mode that has become increasingly practical. In a recent application, cell culture supernatant was monitored on-line with 1-dimensional NMR for trehalose, P-D-pyranose, P-D-furanose, succinate, acetate and uridine.33 In stopped-flow mode, column fractions can also be analyzed by 2-D NMR. Reaction products of the preparation of the neuromuscular blocking compound atracurium besylate were separated on chiral HPLC and detected by 4H NMR.34 Ten isomeric peaks were separated on a cellulose-based phase and identified by online NMR in stopped-flow mode. 

Unfortunately, the number of systems in which it can be established whether Keller s model is realistic for a particular case is severely limited since the original polymer is usually not soluble in the same medium as the ultimate reaction product. In cases where the entire course of the reaction can be followed, as in the basic hydrolysis of polyacrylamide, investigators have analyzed their results by a computer search for the k, k, k values which fit best their kinetic data (9). This, or course, does not answer the question whether the model using these three rate constants provides a full description of a particular case. 

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