主题：【求助】关于在NIST05中使用保留指数数据库的问题？

NISTO5下NIST检索
2-茨醇
CAS:464-45-9

Estimated Kovats RI:
Value: 1138 iu
Confidence interval (Alcohols):  41(50%) 176(95%) iu

Kovats index
1. Value: 1173 iu
Column Type: Capillary
Column Class: Semi-standard non-polar
Active Phase: DB-5MS
Column Length: 30 m
Carrier Gas: He
Column Diameter: 0.25 mm
Phase Thickness: 0.25 um
Data Type: Kovats RI
Program Type: Ramp
Start T: 40 C
End T: 200 C
Heat Rate: 4 K/min
Start Time: 5 min
End Time: 20 min
Source: Yu, E.J.; Kim, T.H.; Kim, K.H.; Lee, H.J. Characterization of aroma-active compounds of Abies nephrolepis (Khingan fir) needles using aroma extract dilution analysis Flavour Fragr. J., 19, 2004, 74-79.

2. Value: 1160 iu
Column Type: Capillary
Column Class: Standard non-polar
Active Phase: BP-1
Column Length: 50 m
Carrier Gas: H2
Column Diameter: 0.33 mm
Data Type: Kovats RI
Program Type: Ramp
Start T: 65 C
End T: 220 C
Heat Rate: 5 K/min
Start Time: 2 min
Source: Ekundayo, O.; Laakso, I.; Adegbola, R.-M.; Oguntimein, B.; Sofowora, A.; Hiltunen, R. Essential oil constituents of Ashanti pepper (Piper guineense) fruits (berries) J. Agri. Food Chem., 36(5), 1988, 880-882.
上面的RI 1138是怎么估算出来的？
是否根据上面的文献？
这与用分子手册查的标准数据库哪个更可靠？