Outlier Sample Analysis on Near Infrared Spectroscopy Determination for Flour Ash

The flour ash was determined by near infrared (NIR) apparatus. Mahalanobis distance method and Monte Carlo cross validation (MCCV) method for abnormal samples removed and using partial least squares (PLS) modeling, Eventually, Mahalanobis distance method for abnormal samples removed, when the weight factor of 1.5, excluding the number of samples is 3 to get the best results, the correlation coefficient (R2) is 92.67, cross validation mean square error (RMSECV) is 0.0485, MCCV method for abnormal samples removed, excluding the number of samples 3 to get the best results, R2 is 94.64, RMSECV is 0.0411. Mahalanobis distance method and MCCV method for abnormal samples removed have improved the accuracy of the model, and MCCV method for flour ash model is more stable and more to improve the accuracy.