Biomedical Engineering Reference
In-Depth Information
Table 1
(continued)
Steroid analysis
Major topics
Reference
Steroid hormones chemical
derivatization, reagent
selection and optimization
Derivatization of steroids to enhance LC/MS
detection, e.g., ESI
+/−
/MS, APCI
+/−
/MS, and
APPI
+/−
/MS.
[
16,
17
]
Steroid hormones by GC/MS
and LC/MS
GC/MS and LC/MS in determination of
androgens, corticoids, estrogens, cholesterol
and related, bile acids, vitamin D and
metabolites, phytosteroids, etc.
[
1
]
Steroid hormones assay
standardization
Immunoassay vs. GC-MS and LC-MS/MS,
validation of assay methodologies, establish-
ing standard pools of steroid hormones in
women and man, utilizing the pools for cross
comparison of various methodologies.
[
18
]
metabolites [
4,
12,
14,
19
]. LC-MS/MS and GC-MS methods are increasingly used
for analyzing steroid hormones due to their high selectivity and sensitivity. The
typical LC-MS/MS methods by direct injection [
20,
21
] and GC-MS methods [
6
]
have limit of quantitation (LOQ) at ng/mL level, and a number of LC-MS/MS [
2,
8,
22
] and GC-MS/MS [
23
] methods are able to achieve LOQ at pg/mL levels when
the steroid hormone samples are chemically derivatized before injection.
Nevertheless, in many cases, clinical diagnostic tests need to determine steroid
hormones at low pg/mL, and even fg/mL levels [
4,
15,
18
]. In order to improve the
MS method sensitivity and sample preparation efficiency, many studies on sample
preparation have been carried out, including deconjugation, extraction, and deriva-
tization. Different chromatographic techniques and MS detection modes have also
been investigated.
On the other hand, many LC-MS/MS and GC-MS methodologies and their
applications to steroid hormone analyses have been developed for the purpose of
scientific research or specific studies only, while they might not have been validated
according to regulatory guidelines, and their results might not correlate with those
from the widely accepted bioanalytical techniques, e.g., IA and RIA. Therefore,
standardization of the LC-MS/MS and GC-MS technologies and methodologies,
including facilities, instruments, reference standards, procedures, data system, etc.,
plays a critical role in transferring the LC-MS/MS and GC-MS technologies to
daily testing procedures for clinical diagnosis, sports antidoping screening, food
safety control, and analysis of environmental contaminations in water and
sediments. Only until their specificity, accuracy, precision, calibration mode,
sensitivity, and robustness are validated according to regulatory guidelines, and the
test results are comparable or consistent with those obtained from the existing
techniques such as IA and RIA, the LC-MS/MS and GC-MS/MS techniques may
not be accepted as reliable clinical diagnostic methodologies for steroid hormone
determination [
18
] .
