scholarly journals Determination ofMagnesium Stearate in Capsule- or Tablet-Type Supplements

2006 ◽  
Vol 89 (2) ◽  
pp. 458-461 ◽  
Author(s):  
Yoko Uematsu ◽  
Mami Ogimoto ◽  
Junichirou Kabashima ◽  
Kouichi Ito ◽  
Kazuo Yasuda
Keyword(s):  
Gas Chromatography ◽  
Stearic Acid ◽  
Cation Exchange ◽  
Acid Concentration ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Magnesium Stearate ◽  
Positive Error ◽  
Simple Method

Abstract A simple method for the determination of magnesium stearate in capsule- or tablet-type supplements was developed. Free stearic acid in the sample was removed by extraction with tetrahydrofuran. The remaining stearate was converted to stearic acid by reaction with a cation-exchange resin. The resulting stearic acid was determined by gas chromatography with a polar column. Esters of stearic acid were not converted to stearic acid and would not cause a positive error in the amount of stearate. The amount of magnesium stearate was calculated based on the stearic acid concentration thus obtained. Magnesium stearate levels in 5 out of 25 supplements exceeded 2500 g/g, which indicated the possible admixture of magnesium stearate.

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.

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