Column-switching high-performance liquid chromatographic system with a laser-induced fluorimetric detector for direct, automated assay of salivary cortisol

Okumura, Tatsuya; Nakajima, Yuki; Takamatsu, Tasuku; Matsuoka, Makoto

doi:10.1016/0378-4347(95)00132-3

Cited by 25 publications

(17 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only one cortisol derivative was reported in the previous articles using similar derivatization method with sulfuric acid [21,25,28]; however, we repeated the experiment according to the description of the previous article [25] using proposed PFSPE column to extract the derivative, and two sulfuric acid-ethanol derivatives of cortisol were found under the chromatographic conditions proposed in the previous article. In the comparison of the extraction efficiency between PFSPE and the traditional LLE, it was found that both methods could extract the two derivatives, but the conventional method possessed much lower extraction efficiencies, especially for the first eluted derivative.…”

Section: Comparison Of the Extraction Methods For The Cortisol And Dementioning

confidence: 99%

“…Moreover, there are some methods based on HPLC with fluorescence detection (HPLC-FLU) or HPLC-UV, which have been applied in assay of salivary cortisol [20,21]. HPLC-UV method [20] provides simple assay process; however, its sensitivity (the LOD is about 2 mg/L) and selectivity for cortisol are not appropriate for psychological stress research due to unsatisfactory sensitivity and selectivity.…”

Section: Introductionmentioning

confidence: 99%

“…In HPLC-FLU, sulfuric acid-induced rearrangement to fluorescing derivatives offers a higher sensitivity and a simpler procedure than other prelabeling reagent. The successful application of HPLC-FLU method to saliva is column-switching HPLC system reported by Okumura [21]; however, the system consists of five pumps to solve the problem that the reaction is time dependent and the fluorescent derivative is unstable, thus procedural complication and additional equipment are the limiting factors for its applicability in common laboratories.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Application of nanofiber‐packed SPE for determination of salivary‐free cortisol using fluorescence precolumn derivatization and HPLC detection

Chen

Kang

Sun

et al. 2010

J of Separation Science

View full text Add to dashboard Cite

Salivary cortisol has emerged as an easy-to-collect biologic marker of stress in many researches. In this study, we present a method for the determination of salivary-free cortisol using HPLC method with fluorescence precolumn derivatization, which is based on a novel extraction from the strongly acidic medium (fluorescent derivatives of cortisol in sulfuric acid medium) by electrospun polystyrene nanofibers packed SPE. For high-throughput sample extraction, an array pretreatment device based on nanofibers packed SPE micro-column was designed. The LOD of cortisol was 0.01 microg/L (S/N=3). The RSDs (n=6) for all analytes were below 8.0%, and the recoveries were 110, 102.4, and 99.4% (n=3) for saliva spiked with 0.1, 10, and 20 microg/L of cortisol, respectively. The proposed method was then successfully applied in the determination of free cortisol in human saliva. The salivary cortisol concentrations in the real samples ranged from 0.22 to 7.45 microg/L. The nanofiber-packed SPE overcame the low extraction recovery and bad clean-up effect of the conventional methods, and increased the sensitivity and selectivity of the method.

show abstract

Section: Comparison Of the Extraction Methods For The Cortisol And Dementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of nanofiber‐packed SPE for determination of salivary‐free cortisol using fluorescence precolumn derivatization and HPLC detection

Chen

Kang

Sun

et al. 2010

J of Separation Science

View full text Add to dashboard Cite

show abstract

“…Hydrocortisone and prednisolone were analyzed by HPLC/UV using a switching column method, following the liquid-liquid extraction (Okumura et al, 1995;van der Hoeven et al, 1997;Kim et al, 2005). A Capcell pak MF C 8 (4.6 × 50 mm) and a Capcell Pak MF C 18 (2.0 × 35 mm) were used as a pre-column and a trap-column (Shiseido, Tokyo, Japan), respectively.…”

Section: Chromatographic Conditionmentioning

confidence: 99%

Bioequivalence Study of Hydrocortisone Tablets while Secretion of Endogenous Cortisol Suppressed

Ok¹,

Lee²,

Shin³

2008

Biomolecules and Therapeutics

View full text Add to dashboard Cite

− The purpose of this study was to evaluate the bioequivalence of the test (Daewoo Hydrocortisone 10 mg, Daewoo Pharm. Co., Busan, Korea) and reference (Jenapharm Hydrocortisone 10 mg, JayTech Biogen, Seoul, Korea) hydrocortisone tablets. Twenty-four healthy male Korean volunteers were divided into two groups with a randomized 2×2 cross-over design. In order to suppress the endogenous cortisol secretion, a single oral dose of Dexamethasone (4 mg) was administered 10 hr prior to hydrocortisone administration. Blood samples were withdrawn for 10 hr at the predetermined intervals after a single oral dose of hydrocortisone (20 mg). The serum concentration of hydrocortisone was analyzed by HPLC/UV using a column switching method after liquid-liquid extraction process. The pharmacokinetic parameters (AUC 0~10hr , C max , and T max ) of the test and reference hydrocortisone tablets were determined while the secretion of endogenous cortisol was being suppressed. The pharmacokinetic parameters of the test tablet were not statistically different from those of the reference tablet at α value was 0.05. The 90% confidence intervals for the average ratio (test/reference) of AUC 0~10hr and C max were within the Korea Food and Drug Administration acceptance range of 0.80-1. 25 (0.890 .99 and 0.86~0.99 for AUC 0~10hr and C max , respectively). Therefore it was concluded that the test tablet, Daewoo Hydrocortisone tablet was bioequivalent to the reference tablet, Jenapharm Hydrocortisone tablet.

show abstract

“…The determination of steroids in the body continues to be an analytical challenge not only because their chemical structures are similar but also because their levels in biological fluids are extremely low. Most studies reported to date have employed RIA [1,2], fluorimetry [3,4], HPLC [5][6][7][8], LC-ESI MS [9], GC/negative ion chemical ionization MS [10], and CE [11][12][13][14][15][16][17][18] for the measurement. Each of these methods has unique advantages and disadvantages with respect to sensitivity, precision, and simplicity of use.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the use of anionic and cationic surfactants for the separation of steroids based on MEKC and sweeping‐MEKC modes

Shen

Lin

2006

Electrophoresis

View full text Add to dashboard Cite

In attempts to improve the selectivity and sensitivity of steroid separation and to determine their migration order, a comparison of the use of anionic and cationic surfactants based on the MEKC and sweeping-MEKC modes was made. A mixture of six steroids (progesterone, 17-hydroxy progesterone, 11-deoxycortisol, corticosterone, cortisone, and cortisol) could be separated and detected by means of the CE/UV-absorption method. The order of migration time for these steroids was compared under various conditions, including acidic/alkaline buffers, anionic/cationic surfactants, and positive/negative applied voltage, causing the direction of the EOF and the migration of micelles to change. The major rules for generally predicting the migration order of steroids are summarized. The detection limits were significantly improved when the sweeping-MEKC mode was applied.

show abstract

Column-switching high-performance liquid chromatographic system with a laser-induced fluorimetric detector for direct, automated assay of salivary cortisol

Cited by 25 publications

References 24 publications

Application of nanofiber‐packed SPE for determination of salivary‐free cortisol using fluorescence precolumn derivatization and HPLC detection

Application of nanofiber‐packed SPE for determination of salivary‐free cortisol using fluorescence precolumn derivatization and HPLC detection

Bioequivalence Study of Hydrocortisone Tablets while Secretion of Endogenous Cortisol Suppressed

Comparison of the use of anionic and cationic surfactants for the separation of steroids based on MEKC and sweeping‐MEKC modes

Contact Info

Product

Resources

About