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. Author manuscript; available in PMC: 2016 Apr 1.
Published in final edited form as: Steroids. 2015 Jan 21;96:89–94. doi: 10.1016/j.steroids.2015.01.007

Table 1.

Mass Spectrometry Method Characteristics

Analyte Mass Transitions
(Quantifier/Qualifier)
m/z 		LC tR
(min)c 		Ext.
Rec.
(%)d 		LOD
(pg)e 		LOQ
(pg)e 		Within
Assay
Var.
(%)f 		Bet.
Assay
Var.
(%)f 		Serum
LOQ
(sLOQ)
(pg/ml)g,i 		CoV
at
sLOQ
(%)
E3a 287.2 Inline graphic 171.1/145.1 4.7 96 1.0 1.0 6.5 3.0 30.0 5.9
[D4]-E3 291.2 Inline graphic 173.1/147.1
E1a 269.2 Inline graphic 145.1/183.1 7.1 86 0.1 0.3 6.9 4.5 1.0 4.3
[D4]-E1 273.2 Inline graphic 147.1/187.1
E2a 271.2 Inline graphic 183.1/145.1 7.3 96 0.3 1.0 8.2 3.0 3.0 3.4
[D4]-E2 275.2 Inline graphic 187.1/147.1
Tb 289.2 Inline graphic 97.1/109.1 7.6 82 0.3 1.0 7.2 3.5 30.0 8.5
[13C3]-T 292.2 Inline graphic 100.1/112.1
P4b 315.2 Inline graphic 97.1/109.1 9.0 50 0.3 1.0 7.3 2.9 N/Ah N/Ah
[D9]-P4 324.2 Inline graphic 100.1/113.1
a

Estrone, estradiol, and estriol are analyzed as negative ions.

b

Testosterone and progesterone are analyzed as positive ions.

c

Liquid chromatography retention time.

d

Extraction recovery.

e

Limit of Detection (LOD) and Quantitation (LOQ) calculated from standard curve (methanol solvent).

f

Calculated from standard curves (within assay variability n = 5, between assay variability n = 3).

g

LOQ and variability calculated from addition of standards to unaltered serum samples (n = 3).

h

Cannot determine due to chemical interference (see Figure 1)

i

To convert E3 (pg/ml) to pM, multiply by 3.47, E2: 3.67, E1: 3.72, T: 3.47, P4: 3.18.