Color Development Reaction Research of Melamine in Milk

2011 ◽  
Vol 393-395 ◽  
pp. 1133-1138
Author(s):  
Xi Quan Sun ◽  
Sheng Lin Qiao ◽  
Zheng Xiao Liu ◽  
Ling Le Kong
Keyword(s):  
Exchange Resin ◽  
Detection Method ◽  
Low Cost ◽  
Cation Exchange Resin ◽  
Volume Ratio ◽  
Centrifugal Separation ◽  
Resin Column ◽  
Color Development ◽  
Extraction Agent

According to the color development reaction between starch/iodine reagent and products which obtained by fumigating melamine with chlorine, a method for determination of melamine in milk was put forward. The conditions of method were researched. The best conditions are as follows. Volume ratio of milk and extraction agent is 1:1. 5, dissolved with ultrasonic washer for 5 minutes, centrifugal separation 4000r/min for 5 minutes, extracted by C008 cation exchange resin column. The results are as follows: detection limit is 10mg/L, the linear range is 25-250 mg/L, related coefficient r is 0.994, coefficient of recovery is 94%-110%, and relatively standard deviation is 0.9%. This method is easy handling, cheap equipment, good practicability and recovery, can be used as low cost detection method.

scholarly journals Determination of Trace Amounts of Metals in Public Water by Using Cation-Exchange Resin Column. II. Distribution of Heavy Metals in the Sagami River

Eisei kagaku ◽  
1977 ◽  
Vol 23 (5) ◽  
pp. 314-318
Author(s):  
AKIRA ISHIMARU ◽  
SHINICHI ISHIWATA ◽  
YOSHIAKI SUYAMA ◽  
KOJI HIRANO ◽  
YOSUKE SHINO ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Cation Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Resin Column

Collaborative Study and Ion Exchange Method for the Determination of Methyldopa, Chlorothiazide, and Hydrochlorothiazide in Drug Mixtures

1971 ◽  
Vol 54 (3) ◽  
pp. 603-608
Author(s):  
Rod Chu
Keyword(s):  
Standard Deviation ◽  
Ion Exchange ◽  
Exchange Resin ◽  
Collaborative Study ◽  
Cation Exchange Resin ◽  
Resin Column ◽  
Exchange Method ◽  
Average Recovery ◽  
Ion Exchange Method

Abstract A method for the assay of methyldopa with either chlorothiazide or hydrochlorothiazide was studied collaboratively by 8 laboratories. The method involves the use of AG50-4X, 100-200 mesh H+ cation exchange resin to resolve the compounds. The thiazides pass freely through the resin column, while methyldopa is retained and subsequently eluted with 1N methanolic HCl. The components are quantitatively measured by spectrophotometry at 280 (methyldopa), 277 (chlorothiazide), and 270 nm (hydrochlorothiazide). For the methyldopa-chlorothiazide combination, the overall average recovery for methyldopa was 98.5% with a standard deviation of 2.50; and for the methyldopa-hydrochlorothiazide combination, 96.4% with a standard deviation of 2.30. The average recoveries for chlorothiazide and hydrochlorothiazide were 99.6 (standard deviation of 1.14) and 98.8% (standard deviation of 2.92), respectively. The method has been adopted as official first action for the determination of methyldopa and chlorothiazide in combination.

An improved separation scheme for Sr through fluoride coprecipitation combined with a cation-exchange resin from geological samples with high Rb/Sr ratios for high-precision determination of Sr isotope ratios

2020 ◽  
Vol 35 (5) ◽  
pp. 953-960
Author(s):  
Wen-Gang Liu ◽  
Shuang Wei ◽  
Jian Zhang ◽  
Cong Ao ◽  
Fu-Tian Liu ◽  
...  
Keyword(s):  
Cation Exchange ◽  
High Precision ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Separation Scheme ◽  
Geological Samples ◽  
Sr Isotope ◽  
Precision Determination ◽  
High Precision Determination

A new separation method for Sr involving HF coprecipitation combined with AG50 resin from samples with high Rb/Sr ratios.

Ion Exchange Method for Rapid Determination of Alkalinity of Water-Soluble Tea Ash Containing High Levels of Manganese

1980 ◽  
Vol 63 (3) ◽  
pp. 460-461
Author(s):  
Saidul Z Qureshi ◽  
Fadhil M Najib ◽  
Fahmi A Mohammed
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Exchange Resin ◽  
Rapid Determination ◽  
Cation Exchange Resin ◽  
Water Soluble ◽  
Exchange Method ◽  
Strong Cation Exchange ◽  
Ion Exchange Method

Abstract An ion exchange method to determine the alkalinity of water-soluble tea ash containing high levels of manganese is described. A chromatographic column containing a strong cation exchange resin (20–50 mesh) in Na+ form, with a bed volume of 5 mL is used. The present ion exchange method is compared to pH titrations and also to the official AOAC methods (31.012, 31.015, 31.016). Results with the new method are accurate and precise.

Improved Method for Gas-Liquid Chromatographic Determination of Clopidol in Chicken Tissues

1980 ◽  
Vol 63 (6) ◽  
pp. 1211-1214
Author(s):  
Etsuko Suzuki ◽  
Mihoko Matsuda ◽  
Atsushi Momose ◽  
Masaya Namekata
Keyword(s):  
Exchange Resin ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Alumina Column ◽  
Resin Column ◽  
Chicken Tissues ◽  
Liquid Chromatographic Determination ◽  
Low Levels ◽  
Liquid Chromatographic

Abstract A sensitive and specific gas-liquid chromatographic (GLC) method has been developed for determining low levels of clopidol in chicken tissues. Clopidol is extracted from the tissues with methanol, and cleaned up on an alumina column and an anion exchange resin column with 0.1% acetic acid–methanol as eluate. Clopidol is methylated with diazomethane, and then determined by GLC. 2,4-Dinitro-l-chlorobenzene is used as an internal standard. The method is applicable to levels as low as 2 ppb in chicken tissues. Recoveries of 2–20 ppb clopidol added to tissues averaged 87% for muscle, 84% for liver, 80% for kidney, and 76% for fat.

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