Thermo Scientific Orion AquaMate UV-Vis, User Manual, Page: 211 / 213

Appendix A
|
General Instrument Information
Thermo Scientific Orion AquaMate Spectrophotometer User Manual | 211
Calculation Calculation Equation
Statistics (Linear
regression general
case)
σ =
�∑
( 𝑦
𝑖
− 𝑦
�
)
2
N − n − 1
Where:
N = Degree of polynomial
𝑟 =
| 𝑆𝑆𝑋𝑌 |
�𝑆𝑄𝑋 ∗ 𝑆𝑄𝑌
The calculation for the correlation coefficient applies only to first order linear
regression curves (first degree polynomials)
Linear regression
through zero model
𝜎 =
�𝑆𝑌𝑌 −
( 𝑎
1
∗ 𝑆𝑋𝑌 )
𝑁 − 1
Absorbance Ratio
𝐴𝑏𝑠𝜆
1
𝐴𝑏𝑠𝜆
2
or
𝐴𝑏𝑠𝜆
1
−𝐴𝑏𝑠
𝑟𝑒𝑓
𝐴𝑏𝑠𝜆
2
− 𝐴𝑏𝑠
𝑟𝑒𝑓
Absorbance Difference
Result = Absλ
1
* factor
1
– Absλ
2
* factor
2
or
Result = (Absλ
1
– Absλ
ref
) * factor
1
– (Absλ
2
– Absλ
ref
) * factor
2
3-Point Net
Baseline correction absorbance =
𝐴
2
− �𝐴
3
+ �
[
𝐴
1
− 𝐴
2
]
∗
𝜆
3
− 𝜆
2
𝜆
3
− 𝜆
1
��
3-Point Net Absorbance Sample Curve:
3-Point Net
(ASTM E16904)
Baseline correction absorbance =
𝐴
2
− �𝐴
3
+ �
[
𝐴
2
− 𝐴
3
]
∗
𝜆
3
− 𝜆
1
𝜆
3
− 𝜆
2
��