Simultaneous determination of five sex hormones in human serum by radioimmunoassay after chromatography on Lipidex-5000.

Abstract We describe a method for determination of pregnenolone, progesterone, 17alpha-hydroxyprogesterone, testosterone, and 5alpha-dihydrotestosterone in 1-2 ml of serum from male or female. Using microcolumns of Lipidex-5000 (hydroxyalkoxypropyl Sephadex, 0.5 g) and light petroleum/chloroform (97/3) as the solvent during chromatography, we resolved these five steroids into four fractions, with pregnenolone and 5alpha-dihydrotestosterone eluting together. By use of selected antibodies, the latter two steroids were also determined specifically. Use of microcolumns allowed minimization of solvent volumes and sample transfers. Consequently, blank values for all the five steroids were negligible. Lowest measureable concentrations (in ng/liter) were: pregnenolone 100, progesterone 25, 17alpha-hydroxyprogesterone 50, testosterone 25, and 5alpha-dihydrotestosterone 25. Intra-assay and inter-assay coefficients of variation ranged from 5 to 9% and 10 to 15%, respectively, for the five steroids. Serum concentrations of these steroids are given for women in the follicular and luteal phases of the menstrual cycle and for women on oral contraceptives of the combination type, as well as for normal men.

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Simultaneous determination of nicotinamide and N 1 ‐methylnicotinamide in human serum by LC‐MS/MS for associating their serum concentrations with obesity

Biomedical Chromatography ◽

10.1002/bmc.5261 ◽

2021 ◽

Author(s):

Jihong Chu ◽

Ming Liu ◽

Guoliang Dai ◽

Changyin Li ◽

Ting Wu ◽

...

Keyword(s):

Human Serum ◽

Simultaneous Determination ◽

Serum Concentrations

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Simultaneous Determination of Chloroquine and Pyrimethamine with Cetirizine in an Active Form and Human Serum by RP-HPLC

Journal of Chromatographic Science ◽

10.1093/chromsci/bmab018 ◽

2021 ◽

Author(s):

Hina Shamshad ◽

Ali Sayqal ◽

Jahan Zeb ◽

Agha Zeeshan Mirza

Keyword(s):

Human Serum ◽

Simultaneous Determination ◽

Active Form ◽

Internal Standard ◽

Hplc Method ◽

Serum Samples ◽

Rp Hplc ◽

Cetirizine Hydrochloride ◽

Bulk Drug

Abstract A simple, accurate and precise RP-HPLC method was developed for the simultaneous determination of chloroquine, pyrimethamine and cetirizine hydrochloride concentrations in bulk drug and human serum. The assay was performed using a mobile phase of methanol: water (70:30) at pH of 2.8 ± 0.05 on the Purospher C-18 column with UV detection at 230 nm and rosuvastatin used as an internal standard. The retention times observed for chloroquine, pyrimethamine and cetirizine hydrochloride were 3.5, 2.5 and 5.5 minutes, respectively. The method was found to be specific for the assayed drugs showing a linear response in the concentration range of 1–100 μg mL−1 with coefficients of determination values of (r = 0.999). The method was developed and validated according to ICH guidelines. The method was used to monitor the serum samples and was found to be sensitive for therapeutic purposes, showing the potential to be a useful tool for routine analysis in laboratories.

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Simultaneous Determination of Human Serum Albumin and Low-Molecular-Weight Thiols after Derivatization with Monobromobimane

Molecules ◽

10.3390/molecules26113321 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3321

Author(s):

Katarzyna Kurpet ◽

Rafał Głowacki ◽

Grażyna Chwatko

Keyword(s):

Molecular Weight ◽

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Simultaneous Determination ◽

Reversed Phase ◽

Fluorescence Labeling ◽

Detector Response ◽

Low Molecular Weight

Biothiols are extremely powerful antioxidants that protect cells against the effects of oxidative stress. They are also considered relevant disease biomarkers, specifically risk factors for cardiovascular disease. In this paper, a new procedure for the simultaneous determination of human serum albumin and low-molecular-weight thiols in plasma is described. The method is based on the pre-column derivatization of analytes with a thiol-specific fluorescence labeling reagent, monobromobimane, followed by separation and quantification through reversed-phase high-performance liquid chromatography with fluorescence detection (excitation, 378 nm; emission, 492 nm). Prior to the derivatization step, the oxidized thiols are converted to their reduced forms by reductive cleavage with sodium borohydride. Linearity in the detector response for total thiols was observed in the following ranges: 1.76–30.0 mg mL−1 for human serum albumin, 0.29–5.0 nmol mL−1 for α-lipoic acid, 1.16–35 nmol mL−1 for glutathione, 9.83–450.0 nmol mL−1 for cysteine, 0.55–40.0 nmol mL−1 for homocysteine, 0.34–50.0 nmol mL−1 for N-acetyl-L-cysteine, and 1.45–45.0 nmol mL−1 for cysteinylglycine. Recovery values of 85.16–119.48% were recorded for all the analytes. The developed method is sensitive, repeatable, and linear within the expected ranges of total thiols. The devised procedure can be applied to plasma samples to monitor biochemical processes in various pathophysiological states.

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