A METHOD FOR THE SIMULTANEOUS DETERMINATION OF 17-OXOSTEROIDS AND 17-HYDROXYCORTICOSTEROIDS IN HUMAN PLASMA

1964 ◽  
Vol 28 (3) ◽  
pp. 289-296 ◽  
Author(s):  
N. DESHPANDE ◽  
R. D. BULBROOK

SUMMARY A simple method for the simultaneous estimation of 17-hydroxycorticosteroids and 17-oxosteroids in human plasma is described. It involves extraction of free corticosteroids, hydrolysis of glucuronosides with β-glucuronidase and solvolysis of sulphates, chromatography on silica gel and colorimetry using microcells. Recoveries of added steroids, using appropriate conjugated compounds were over 80%.

1965 ◽  
Vol 13 (02) ◽  
pp. 484-491
Author(s):  
D. M Adamis ◽  
G. M Maniatis

SummaryThe fibrinolytic and esterolytic activity of the plasma before and after activation with Streptokinase is studied. The inhibitors of plasmin are neutralized by the acidification of the plasma or by the acetone treatment. The inhibitors of the “trypsin like enzymes” are neutralized only by acetone. The hydrolysis of the BAEE by the acetone treated and activated plasma seems to be a satisfactory method for the simultaneous determination of the total (plasmin-plasminogen) activity and the total activity of the (trypsin like enzymes) with arginine exopeptidase activity.


2016 ◽  
Vol 60 (8) ◽  
pp. 4734-4742 ◽  
Author(s):  
Tiphaine Legrand ◽  
Dominique Vodovar ◽  
Nicolas Tournier ◽  
Nihel Khoudour ◽  
Anne Hulin

ABSTRACTA simple and rapid ultra-high-performance liquid chromatography (UHPLC) method using UV detection was developed for the simultaneous determination of eight β-lactam antibiotics in human plasma, including four penicillins, amoxicillin (AMX), cloxacillin (CLX), oxacillin (OXA), and piperacillin (PIP), and four cephalosporins, cefazolin (CFZ), cefepime (FEP), cefotaxime (CTX), and ceftazidime (CAZ). One hundred-microliter samples were spiked with thiopental as an internal standard, and proteins were precipitated by acetonitrile containing 0.1% formic acid. Separation was achieved on a pentafluorophenyl (PFP) column with a mobile phase composed of phosphoric acid (10 mM) and acetonitrile in gradient elution mode at a flow rate of 500 μl/min. Detection was performed at 230 nm for AMX, CLX, OXA, and PIP and 260 nm for CFZ, FEP, CTX, and CAZ. The total analysis time did not exceed 13 min. The method was found to be linear at concentrations ranging from 2 to 100 mg/liter for each compound, and all validation parameters fulfilled international requirements. Between- and within-run accuracy errors ranged from −5.2% to 11.4%, and precision was lower than 14.2%. This simple method requires small-volume samples and can easily be implemented in most clinical laboratories to promote the therapeutic drug monitoring of β-lactam antibiotics. The simultaneous determination of several antibiotics considerably reduces the time to results for clinicians, which may improve treatment efficiency, especially in critically ill patients.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre

In this study, three simple and accurate spectrophotometric methods for simultaneous determination of pyriproxyfen and chlorothalonil residues in cucumbers and cabbages grown in experimental greenhouse were studied. The first method was based on the zero-crossing technique measurement for first and second derivative spectrophotometry. The second method was based on the first derivative of the ratio spectra. However, the third method was based on mean centering of ratio spectra. These procedures lack any previous separation steps. The calibration curves for three spectrophotometric methods are linear in the concentration range of 1–30 μg·mL−1 and 0.5–7 μg·mL−1 for pyriproxyfen and chlorothalonil successively. The recoveries ranged from 82.12–97.40% for pyriproxyfen and 81.51–97.04% for chlorothalonil with relative standard deviations less than 4.95% and 5.45% in all instances for pyriproxyfen and chlorothalonil, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed there were no significant differences between ratio spectra and mean centering methods with the zero-crossing technique. The proposed methods are successfully applied for the simultaneous estimation of the residue of both pesticides in cucumber and cabbage samples.


1975 ◽  
Vol 21 (3) ◽  
pp. 428-431 ◽  
Author(s):  
Godfrey Moses ◽  
Edwin Olivero ◽  
Thomas F Draisey

Abstract An isopropanolic extract of serum can be made suitable for the simultaneous estimation of cholesterol and triglycerides by passing it through a commercially-available chromatographic column containing activated metallic oxides in which alumina predominates. No centrifugation step nor phase separation is required. Use of the purified extract allows existing methods to be simplified and shortened without loss of reproducibility or stability. Results compare well with those obtained by traditional methods.


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