Detection of calcium chloride salts in rubber cublum using Near-Infrared Spectroscopy Technique

Abstract

The objective of this study was to evaluate the ability of fourier-transformed near infrared spectroscopy (FT-NIR) to determine calcium chloride content in rubber cublum. The data were recorded at the wavelengths ranging from 4000-10000 cm-1 for 32 times every 16 cm^-1. The samples of rubber cublum with the diameter of 10 cm were prepared from the latex of 180 ml. A 7×3×3 factorial experiment were assigned in a randomized complete block design with four replications. Factor A consisted of seven levels of calcium chloride, factor B included three levels of moisture content and factor C had three levels of storage temperature. The prediction equation was constructed by using calibration sample group and PLSR technique together with cross-validate technique in Unscrambler 10.1 software program (Camo, Oslo, Norway). The root mean squares of cross-validation (RMSECV) were read to consider PLS factors that provided the lowest RMSECV value and select the most appropriate equation. The calibration and validation equation were developed from the number of factors used in the calibration and validation equation of F20. The Multiple correlation coefficients (R) of calibrations with standard error of calibration (SEC) values of 4.63 was 0.91, whereas the bias-corrected standard error of prediction (SEP) was 4.68 and the average of difference between actual value and NIR-value (bias) values calibration set was 0.18. The best model from original spectra showed the FT-NIR spectroscopy for prediction the calcium chloride salts in rubber cublum.