RÉSUMÉ
To establish the uncertainty evaluation for the quantitative analysis on Xuesaitong Injection by near infrared (NIR) spectroscopy based on β-content tolerance interval (β-CTI). The data of NIR calibration and validation sets were obtained by " I × J × K" full factorial experimental design. The NIR quantification model was established through the PLS algorithm. Based on the validation data, the β-CTI was introduced to estimate the quantitative analysys on uncertainty of NIR, which was compared with the regular β-expectation tolerance interval (β-ETI). Among the seven designed concentration levels, the uncertainty values estimated by the β-ETI are smaller than that estimated by the β-CTI, except for the concentration level of 1.485 mg/mL. Then, the relationship between the relative expanded uncertainty (U) and corresponding concentration (Y) was fitted by lnU= a + b lnY model. When the uncertainty acceptance limit (λ) was set to 20% and the decision profile of uncertainty was plotted, the critical concentration for β-ETI and β-CTI with the acceptable uncertainty could be read as 4.867 and 5.686 mg/mL, respectively. This study has proved that β-CTI can be used to adequately estimate the uncertainty of quantitative analysis by NIR, which provides a new potential tool for the assessment of the accuracy and reliability of NIR spectroscopy.