. Author manuscript; available in PMC: 2022 Dec 6.

Published in final edited form as: Analyst. 2021 Dec 6;146(24):7464–7490. doi: 10.1039/d1an01560e

Table 4.

Age-related difference in Raman spectroscopy properties of cortical bone as determined by peak intensity ratio (PI) and integrated area ratio (IA) with and without 2^nd order Savitky-Golay filter (window size = 21). The highest standard mean difference (d) was bolded for each property.

Property	Method	Filter	6-mo.		20-mo.		Effect size (d)	p-value
Property	Method	Filter	Mean (SD)	COV (%)	Mean (SD)	COV (%)	Effect size (d)	p-value
ν₁PO₄ / Amide I	PI	S-G	16.1 (1.4)	8.95	18.5 (1.7)	9.03	1.549	<0.0001
	PI	None	15.8 (1.5)	9.25	18.4 (1.7)	9.17	1.627	<0.0001
	IA	S-G	6.06 (0.56)	9.29	6.80 (0.54)^a	7.99	1.343	0.0002
	IA	None	6.06 (0.56)	9.28	6.80 (0.54)^a	7.99	1.343	0.0002
ν₁PO₄ / Pro or / (Pro+Hyp)	PI	S-G	21.7 (2.4)	11.1	25.5 (2.1)	8.03	1.679	<0.0001
	PI	None	21.1 (2.1)^a	9.98	25.1 (2.1)	8.22	1.904	<0.0001
	IA	S-G	12.5 (1.3)^a	9.98	14.2 (0.92)	6.46	1.495	<0.0001
	IA	None	12.5 (1.2)^a	9.93	14.2 (0.92)	6.48	1.578	<0.0001
ν₂PO₄ / Amide III	PI	S-G	2.73 (0.32)	11.6	3.11 (0.27)	8.55	1.277	0.0003
	PI	None	2.67 (0.29)	11.1	3.05 (0.26)	8.57	1.375	0.0002
	IA	S-G	1.60 (0.18)	11.4	1.83 (0.19)	10.3	1.244	0.0005
	IA	None	1.60 (0.18)	11.4	1.83 (0.19)	10.3	1.244	0.0005
ν₁PO₄ / CH₂-wag	PI	S-G	12.9 (1.7)^a	12.9	15.4 (1.5)	9.74	1.554	<0.0001
	PI	None	12.7 (1.7)^a	13.4	15.2 (1.5)	9.75	1.554	<0.0001
	IA	S-G	7.95 (1.1)	13.5	9.44 (0.91)	9.61	1.468	<0.0001
	IA	None	7.95 (1.1)	13.5	9.44 (0.91)	9.64	1.468	<0.0001
CO₃ / ν₁PO₄	PI	S-G	0.18 (0.005)	2.88	0.19 (0.003)	1.72	2.394	<0.0001
	PI	None	0.18 (0.005)	2.76	0.19 (0.005)	2.42	2.000	0.0005
	IA	S-G	0.22 (0.005)	2.21	0.23 (0.004)	1.61	2.195	<0.0001
	IA	None	0.22 (0.005)	2.22	0.23 (0.004)	1.61	2.195	<0.0001

Data did not pass the Anderson-Darling normality test; therefore, the p-value was determined by the Mann-Whitney test. Otherwise, the comparison between 6-mo. and 20-mo. old mice was tested for significance using a two-sided t-test.