气相色谱法测定棉纤维的回潮率OA

Due to the abundance of hydroxyl groups in the cotton fiber structure,cotton fibers exhibit remarkable hygroscopicity.Moisture regain,as a core indicator characterizing the hygroscopic properties of fibers,is of critical significance for accurate quantification in cotton fiber trade valuation.Currently,the oven-drying method remains the gold-standard technique for determining the moisture regain of cotton fibers.While this method offers high precision,it suffers from inherent drawbacks of being time-consuming and energy-intensive.Measurement deviations primarily arise from two sources:residual moisture(m1)retained in samples after oven drying and the loss of volatile compounds(m2)during the drying process.A key limitation of existing standards for the oven-drying method is the lack of precise correction strategies to address errors induced by m1 and m2,with inter-laboratory measurement errors remaining unquantified and unresolved.Gas chromatography(GC)is renowned for its high efficiency,rapid analysis,and excellent accuracy,and has demonstrated unique advantages in trace moisture determination across diverse fields,including fertilizers,paper products,and pharmaceuticals.The application of GC technology in cotton fiber moisture regain analysis is expected to effectively mitigate interference from volatile compounds compared to the oven-drying method,thereby eliminating systematic errors caused by m2 and significantly shortening the analytical turnaround time. Therefore,in this study,standard cotton interlining fabrics were selected as the raw material to prepare cotton fiber samples.Anhydrous ethanol was utilized as the extraction solvent,and ultrasonic-assisted extraction(UAE)was employed to extract moisture from the cotton fibers.Subsequent gas chromatographic analysis was performed to develop and validate a novel GC-based method for the determination of cotton fiber moisture regain.This study systematically investigated the effects of different extraction modes,extraction durations,and solvent volumes on moisture extraction efficiency.Critical parameters,including the extraction solvent and column temperature program,were optimized,and a comprehensive methodological validation was conducted on the established GC method.Finally,the results obtained by the proposed method were compared and verified against data generated by the conventional oven-drying method. The experimental results showed that the limit of quantitation(LOQ)of the developed method was 0.12%,with spiked recoveries ranging from 93.0%to 104.3%and relative standard deviations(RSDs)between 0.6%and 4.5%.These findings confirm that the method possesses excellent repeatability,high sensitivity,and good accuracy,providing a novel technical approach for the determination of fiber moisture regain.The absolute deviation between the proposed method and the oven-drying method was in the range of 0.01%to 0.55%,which further validates the feasibility of gas chromatography for the accurate determination of cotton fiber moisture regain.