Chemical Analyses of Washed, Bleached, and Scoured and Bleached Cotton Fiber

Abstract

The chemical compositions of four cottons from a 1982 washed cotton study conducted by the Industry/Government/Union Task Force for Byssinosis Prevention were established by proximate and elemental analyses. The four cotton samples were an unwashed control grown in Mississippi and the corresponding washed, bleached, and scoured/bleached processed cottons. The proximate analyses consisted of serial solvent extractions that furnished data on moisture, water extractables, ethanol extractables, ethanolamine extractables, cellulose, and insoluble residue. Ash production was also measured for the four cotton lint samples. Elemental analyses were performed by x-ray fluorescence for potassium, calcium, magnesium, silicon, phosphorus, and sulfur, and by Kjeldahl analysis for nitrogen. The analyses demonstrate that the water wash and the scouring procedure are responsible for substantially increasing the purity of the cotton fiber. The level of water extractables was reduced by the water washing process, while the level of ethanolamine extractables was reduced by the scouring process. The washed cotton sample contained much smaller amounts of potassium and magnesium compounds than the unwashed control. Ash was reduced to approximately the same level by each of the washing processes.The nitrogen and calcium contents dropped steadily with increasing severity of processing conditions. The changes in chemical composition of cotton lint on processing are related to the layered structured of the cotton fiber. The Cotton Quality Research Station, USDA, and the Division of Respiratory Disease Studies, NIOSH, have determined the effects that dusts from these cottons have on pulmonary function in a group of human volunteers through measurements of the change in forced expiratory volume in one second (FEV 1 ) on exposure to dust generated by carding the cotton samples. All three processed cottons were considerably less active than the unwashed control. Many of the chemical composition parameters showed a marked decrease with water washing alone.In 1973, Merchant and co-workers reported a series oaf experiments demonstrating that thorough washing of cotton prior to carding in a textile mill completely eliminated the biological activity of card dust in a human panel [30]. They also found that carding washed cotton generated a lower fine dust concentration (0.16 mg/m3) than carding raw cotton (0.89 Mg/M3), but the washed cotton was difficult to process in the mill. Since that time, human challenge experiments with dust from a variety of washed and raw cottons have shown that washing cotton prior to carding substantially reduces its ability to cause lung function decrements [ 1, 2, 3, 4, 9, 31, 34, 39], while processing experiments have corroborated the work of Merchant et al. in decreased dust production by washed cotton [5, 23, 26, 27, 36, , 37, 39, 45]. The Cotton Quality Research Station, USDA, Clemson, South Carolina and the Division of Respiratory Disease Studies, NIOSH, Morgantown, West Virginia, have conducted several washed c...

Atomic force microscopy of cotton fiber cell wall surfaces in air and water: quantitative and qualitative aspects

“…This conclusion correlates well with our diculty in ®nding signi®cant dierences in the small fractal segments (Table 3). The unexpected signi®cant dierence observed between A-and B-®bers in Table 5 may be due to morphological changes caused by the extraction of a wide range of chemical species from the B-®bers during treatment (Domelsmith et al 1986). Taken as a whole the small-scan data show that relatively small features are of great utility for the quantitative dierentiation of biological surfaces.…”

Endotoxin Eradication Techniques and Their Effect on Lint Chemical Constituents

“…Similar views were expressed by Rousselle et al (1996) who noted that water extracted some inorganic salts, sugars and proteins from cotton samples. Domelsmith et al (1986) reported that the nitrogen content of the unwashed sample was 0.16% (1.0% protein), whereas the washed cotton contained 0.03-0.11% nitrogen (0.19-0.69% protein).…”

“…The percentage was calculated on dry basis of raw cotton as suggested by AOAC (1984AOAC ( , 1998. Domelsmith et al (1986) found that unwashed cotton contained 87% cellulose while washing and bleaching process increase the purity to approximately 88 to 89 percent. The present results are also supported by the findings of Hamby (1965).…”

“…Different techniques were adopted in the pot to reduce the Byssinogenic potential of raw cotton and it ie generally agreed that the causatives are water soluble materials. Domelsmith et al (1986) found that the unwashed cotton sample was 87 percent cellulose; washing and bleaching increased the purity of cellulose upto 88-89 percent approximately. Analysis of cotton lint has shown that major constituent of cotton fibre was cellulose (Hamby, 1965).…”

“…Further it was reported by that medium stapled cottons grown at Faisalabad differed significantly in cellulose content with high range from 85.17 to 93.31%. Protein and Ash content are found lowered due to washing treatment Domelsmith et al (1986), Only the steaming or autoclaving to raw cotton was thought to be the most suitable method for the removal of endotoxin. This idea came from dapyrogenation of laboratory instrument and glassware.…”