Table 1 Intensity ratios of Ca and O to P at 15 and 5 kV from the Mini-SEM and FE-SEM. (Mean, SD = standard deviation. RSD = relative standard deviation (SD/Mean × 100(%))

Mini-SEM (W source)

SAp

Ca/P

1.40

0.04

2.94

Ca/P

0.05

0.02

43.33

O/P

1.17

0.36

31.12

O/P

4.92

0.69

14.03

BAp

Ca/P

1.41

0.14

10.00

Ca/P

0.15

0.11

75.44

O/P

0.51

0.29

58.09

O/P

5.98

2.14

35.69

MAp

Ca/P

1.43

0.05

3.28

Ca/P

0.03

0.03

75.15

O/P

0.83

0.34

40.78

O/P

4.60

0.79

17.07

FAp

Ca/P

1.93

0.61

31.42

Ca/P

0.14

0.10

71.97

O/P

1.07

0.49

46.16

O/P

6.88

3.21

46.67

FE-SEM

SAp

Ca/P

1.54

0.03

2.10

Ca/P

0.29

0.02

6.79

O/P

1.47

0.20

13.71

O/P

3.48

0.21

6.04

BAp

Ca/P

1.46

0.03

1.78

Ca/P

0.29

0.04

14.20

O/P

1.26

0.27

21.35

O/P

3.58

0.45

12.63

MAp

Ca/P

1.51

0.03

1.63

Ca/P

0.29

0.02

7.12

O/P

1.10

0.15

13.53

O/P

3.36

0.31

9.34

FAp

Ca/P

1.76

0.19

10.83

Ca/P

0.34

0.03

8.59

O/P

1.60

0.23

14.24

O/P

5.58

2.21

39.69