Potassium: A New Marker for Washed Cotton

Abstract

Potassium salts are readily removed from raw cotton by washing the cotton with water. The potassium contents of cotton samples determined by ion-selective electrode, atomic absorption, and x-ray fluorescence methods confirmed that washed samples had low levels of potassium compared to unwashed samples. A sodium cobaltinitrite spot test for potassium is consistently positive for unwashed cotton samples and negative for washed cotton samples. Thus, the potassium content can serve as a marker for washed cotton.