Ethylbutyric acid

Hydrolytic cleavage plays an important role in the metabolic fate of both carbromal (4.210) and bromisoval (4.213). A product of hydrolysis of carbro-mal, 2-bromo-2-ethylbutyramide (4.211), was isolated from the urine of patients intoxicated with carbromal as well as from the urine of rats, mice, and dogs dosed with the drug [138], A suspected further metabolite is 2-bromo-2-ethylbutyric acid (4.212). Other metabolic transformations of carbromal involve hydroxylation and debromination. 

We experimented firstly with a Phenomenex Rezex ROA-Organic Acid 300 X 7.8 mm column with a Rezex Organic Acid 50 x 7.8 mm guard column the mobile phase was 0.013 N (0.0065 M) H2SO4. UV detection was at 215 nm, the flowrate 0.6 ml min, column temperature 35°C and injection volume 20 pi. The internal standard was 2-ethylbutyric acid. The lactic acid peak was preceded by a partially overlapping, probably succinic acid peak the... 

Fig. 8.5. HPLC chromatogram of a first-out silage juice using a Rezex ROA-organic acid column. Identity a, laotio aoid b, formic acid c, acetic acid d, propionic acid e, n-butyric acid f, 2-ethylbutyric acid (internal standard).

A N-Dimethylglycine (0) 3,5-Dinitrobenzoic acid (0) 2-Ethylbutyric acid (0) 5-Ethyl-5-phenylbarbituric acid (0) Fluoroacetic acid (0)... 

SYNS 2-ETH X BUTANOIC ACID a-ETHYLBUTYRIC ACID 2-ETHYLBUTYRIC ACID (FCC) FEMA No. 2429 3-PENTANECARBOXYLIC ACID... 

Hazard Toxic by ingestion, diethylacetic acid. See 2-ethylbutyric acid. 

Dimethylbutyric acid 10% 2, 3-Dimethylbutyric acid 5% 2-Ethylbutyric acid 8% 2-Methylvaleric acid 2% 3-Methylvaleric acid... 

Ethylbutyric acid, 216 Ethyl chloroformate, 191, 193 Ethyl cinnamate, cis and trans, 197 Ethyl frans-cinnamate, 171... 

E.18) Butanoic acid, 2-ethyl-, 2-ethylbutanoic acid, 2-ethylbutyric acid, diethylacetic acid 88-09-5] FEMA 2429... 

In these studies, the manganese complex was generated in situ from added manganese and ligand. In 1991, Saadeh et al. reported the preparation and isolation of complexes with a-hydroxy acids, for example lactic acid, 2-hydroxyisobutyric acid (HIB) and 2-hydroxy-2-ethylbutyric acid (HEB) (425). The latter two ligands led to Mn1 complexes with 06 first coordination spheres, whereas Mnin complexes were prepared and characterized with lactic acid. The crystal structure of the complex with HIB shows it to be two MnIVL2 units that are... 

Ethylbutyric acid as internal standard, weighted least square calibration curve Only few real samples, detection limits for standards in deionized water... 

VFA analysis with headspace introduction has been explored as an alternative to direct aqueous injections. The method was developed for routine analysis of wastewater. Carry-over effects were minimized by using three aquatic wash cycles in between sample injections and headspace matrix effects are accounted for by employing 2-ethylbutyric acid as internal standard. However, the authors advise that standard addition should be employed if severe sample matrix effects are observed. ... 

Several papers investigated the use of SPME for VFA analysis in wastewater and in air. Briefly, a fiber is exposed to the sample headspace or inserted directly into the sample. Analytes adsorb onto the fiber and are subsequently desorbed at high temperatures in the GC injection port. SPME is a solvent-free technique which introduces less potential contaminants into the GC compared to direct injections. SPME is also rapid since no further sample preparation steps are required. It may be used for routine analysis provided that the specific autosampler required for this method is available and that the optimized method conditions are suitable for autosampler application. Further information on principles and other applications of this technique can be found elsewhere. " " Parameters which have been optimized for VFA analysis are fiber coating, fiber exposure time, sample temperature, sample pH, sample agitation, potential salt addition, and desorption parameters. Surrogate standards employed for VFA analysis were 2-ethylbutyric acids for GC/FID or GC/MS and C-labeled organic acids for GC/MS. The method was optimized using standards in deionized water and only a few wastewater samples were analyzed as examples. 

Ethyl butyrate 2-Ethylbutyric acid Ethyl isobutyrate 2-Ethyl-2-methyl-l,3-dioxolane Hexanoic acid... 

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