scholarly journals Determination of small amounts of ethylene chloride in benzene using a substitution reaction with methanolic potassium hydroxide

1973 ◽  
Vol 22 (7) ◽  
pp. 909-913
Author(s):  
Goro HIHARA ◽  
Miharu NAGATA
Keyword(s):  
Substitution Reaction ◽  
Potassium Hydroxide ◽  
Ethylene Chloride

Spectrophotometric Determination of Carbaryl in Grains

1982 ◽  
Vol 65 (1) ◽  
pp. 32-34
Author(s):  
Kalapanda M Appaiah ◽  
Rasamsetti Ramakrishna ◽  
Kadari R Subbarao ◽  
Omprakash Kapur
Keyword(s):  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Potassium Hydroxide ◽  
Oxidizing Agent ◽  
Spectrophotometric Measurement ◽  
The Relationship ◽  
Hydrolysis Of

Abstract A method has been developed for determining carbaryl (1-naphthyl N-methyl carbamate) in grains, based on hydrolysis of carbaryl with methanolic potassium hydroxide to 1-naphthol, reaction with 4-aminophenazone in the presence of alkaline oxidizing agent, and spectrophotometric measurement at the absorption maximum at 475 nm. The relationship between absorbance and concentration is linear in the range of 0.5-20 μg/mL. The method can be applied to levels as low as 0.3 ppm carbaryl in grains.

Problems Involved in the Quantitative Extraction of Glycogen and High-Energy Phosphorus Compounds in Frozen Cod Muscle

1968 ◽  
Vol 25 (8) ◽  
pp. 1525-1538 ◽  
Author(s):  
Sandra S. Nowlan ◽  
W. J. Dyer ◽  
Doris I. Fraser
Keyword(s):  
Liquid Nitrogen ◽  
Perchloric Acid ◽  
Potassium Hydroxide ◽  
Sampling Error ◽  
High Energy ◽  
Phosphorus Compounds ◽  
Quantitative Extraction ◽  
Sampling Procedures ◽  
Acid Extractant

Extraction of cod muscle with 0.3 N perchloric acid followed by digestion of the residue in potassium hydroxide yielded an average of 16% more total glycogen than did classical digestion with 30% KOH. However, the differences tended to be less at higher glycogen levels. It was suggested that glycogen may be partially degraded during digestion with KOH, although no glycogenosis occurred during contact with alkali prior to heating. The proportion of residual glycogen not extracted by acid varied from 23% in unfrozen muscle to about 40% in liquid nitrogen-frozen and in slowly frozen muscle.Significant degradation of glycogen and high energy phosphorus compounds in frozen prerigor cod muscle was avoided by weighing samples in insulated beakers chilled by liquid nitrogen to prevent warming or thawing, and by homogenizing immediately on addition of acid extractant. Extraction with acid enabled the simultaneous determination of glycogen and phosphorus compounds on the same sample. Special sampling procedures were employed to reduce the sampling error due to variation in glycogen distribution along the fillet.

Polarographic Determination of Traces of Gold in Blood and Serum

1965 ◽  
Vol 11 (4) ◽  
pp. 459-464 ◽  
Author(s):  
Gary D Christian
Keyword(s):  
Relative Error ◽  
Biological Samples ◽  
Potassium Hydroxide ◽  
Polarographic Determination ◽  
Polarographic Method ◽  
Serum Samples ◽  
Gold Sample

Abstract A polarographic method for the determination of as little as 1 µg. of gold in blood and serum samples is described. The relative error is 2.1%. After the sample is dry ashed at 550°, the gold is extracted into ether as the chloride, to separate it from interfering copper and iron. A polarogram of the gold sample is obtained in 2 M potassium hydroxide. The method should be applicable to the determination of gold in other biological samples containing interfering elements.

Liquid Chromatographic Determination of Vitamin D in Animal Feeds and Premixes

1992 ◽  
Vol 75 (5) ◽  
pp. 812-814 ◽  
Author(s):  
Vipin K Agarwal
Keyword(s):  
Vitamin D ◽  
Mobile Phase ◽  
Potassium Hydroxide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Ultraviolet Detection ◽  
Animal Feeds ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for the determination of vitamin D (D2 + D3) in animal feeds and premixes. The sample is saponified with potassium hydroxide, and vitamin D is extracted with hexane and isomerized to isotachysterol with 10M HCI in 2-butanol. LC determination of isotachysterol to quantitate vitamin D is carried out on a reversed-phase column with acetonitrilemethanol (90 +10) as the mobile phase and ultraviolet detection at 301 nm. The detection limit of the method is 1 lU/g. This method can also be used for the determination of vitamin D2 and D3 separately.

Sign in / Sign up

Export Citation Format

Share Document