光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2015年
8期
2147-2153
,共7页
中红外%近红外%拉曼%预处理方法%光谱范围%定量%准确性
中紅外%近紅外%拉曼%預處理方法%光譜範圍%定量%準確性
중홍외%근홍외%랍만%예처리방법%광보범위%정량%준학성
Mid-infrared%Near-infrared%Raman%Pre-processing method%Spectral region%Quantification%Accuracy
分别利用中红外（mid‐infrared ，MIR）、近红外（near‐infrared ，NIR）和拉曼光谱（Raman）采集了31种不同比例的低密度聚乙烯／聚丙烯（LDPE／PP）共混物样本的光谱，利用偏最小二乘法（partial least‐square ， PLS ）建立了光谱数据与LDPE含量的模型，研究了不同光谱范围和预处理方法对模型准确性的影响，并比较了三种光谱定量测量的准确性。结果表明，对于光谱差异小、存在噪音或基线干扰的谱图，预处理方法和光谱范围对模型的准确性均有较大的影响；经过三种预处理以及选择合适的光谱范围建立的模型决定系数（R2）分别从未处理前的0.8876，0.8493和0.8757提升到0.9906，0.9973和0.9972，校正均方根误差（root mean square error of calibration ，RMSEC）则分别从10.15，11.75和10.67降低到2.941，1.561和1.598；三种光谱在经过预处理之后均能够较好地定量测量LDPE的含量，NIR和Raman模型准确性更高，由于两者的测量速度快，因此尤其适合于进行快速、准确的定量测量。
分彆利用中紅外（mid‐infrared ，MIR）、近紅外（near‐infrared ，NIR）和拉曼光譜（Raman）採集瞭31種不同比例的低密度聚乙烯／聚丙烯（LDPE／PP）共混物樣本的光譜，利用偏最小二乘法（partial least‐square ， PLS ）建立瞭光譜數據與LDPE含量的模型，研究瞭不同光譜範圍和預處理方法對模型準確性的影響，併比較瞭三種光譜定量測量的準確性。結果錶明，對于光譜差異小、存在譟音或基線榦擾的譜圖，預處理方法和光譜範圍對模型的準確性均有較大的影響；經過三種預處理以及選擇閤適的光譜範圍建立的模型決定繫數（R2）分彆從未處理前的0.8876，0.8493和0.8757提升到0.9906，0.9973和0.9972，校正均方根誤差（root mean square error of calibration ，RMSEC）則分彆從10.15，11.75和10.67降低到2.941，1.561和1.598；三種光譜在經過預處理之後均能夠較好地定量測量LDPE的含量，NIR和Raman模型準確性更高，由于兩者的測量速度快，因此尤其適閤于進行快速、準確的定量測量。
분별이용중홍외（mid‐infrared ，MIR）、근홍외（near‐infrared ，NIR）화랍만광보（Raman）채집료31충불동비례적저밀도취을희／취병희（LDPE／PP）공혼물양본적광보，이용편최소이승법（partial least‐square ， PLS ）건립료광보수거여LDPE함량적모형，연구료불동광보범위화예처리방법대모형준학성적영향，병비교료삼충광보정량측량적준학성。결과표명，대우광보차이소、존재조음혹기선간우적보도，예처리방법화광보범위대모형적준학성균유교대적영향；경과삼충예처리이급선택합괄적광보범위건립적모형결정계수（R2）분별종미처리전적0.8876，0.8493화0.8757제승도0.9906，0.9973화0.9972，교정균방근오차（root mean square error of calibration ，RMSEC）칙분별종10.15，11.75화10.67강저도2.941，1.561화1.598；삼충광보재경과예처리지후균능구교호지정량측량LDPE적함량，NIR화Raman모형준학성경고，유우량자적측량속도쾌，인차우기괄합우진행쾌속、준학적정량측량。
This paper presented an application of mid‐infrared (MIR) ,near‐infrared (NIR) and Raman spectroscopies for collec‐ting the spectra of 31 kinds of low density polyethylene/polyprolene (LDPE/PP) samples with different proportions .The differ‐ent pre‐processing methods (multiplicative scatter correction ,mean centering and Savitzky‐Golay first derivative ) and spectral region were explored to develop partial least‐squares (PLS) model for LDPE ,their influence on the accuracy of PLS model also being discussed .Three spectroscopies were compared about the accuracy of quantitative measurement .Consequently ,the pre‐processing methods and spectral region have a great impact on the accuracy of PLS model ,especially the spectra with subtle difference ,random noise and baseline variation .After being pre‐processed and spectral region selected ,the calibration model of MIR ,NIR and Raman exhibited R2/RMSEC values of 0.990 6/2.941 ,0.997 3/1.561 and 0.997 2/1.598 respectively ,which corrsponding to 0.887 6/10.15 ,0.849 3/11.75 and 0.875 7/10.67 before any treatment .The results also suggested MIR ,NIR and Raman are three strong tools to predict the content of LDPE in LDPE/PP blend .However ,NIR and Raman showed higher accuracy after being pre‐processed and more suitability to fast quantitative characterization due to their high measuring speed .
