Determination of Tuaminoheptane in Doping Control Urine Samples

2007 ◽  
Vol 13 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Mario Thevis ◽  
Gerd Sigmund ◽  
Anja Koch ◽  
Wilhelm Schänzer
Keyword(s):  
Drug Testing ◽  
Limit Of Detection ◽  
Urine Samples ◽  
Fragment Ions ◽  
Liquid Liquid Extraction ◽  
In Doping ◽  
Aldehydes And Ketones ◽  
Characteristic Fragment ◽  
World Anti Doping Agency

Since January 2007, the list of prohibited substances established by the World Anti-Doping Agency includes the sympathomimetic compound tuaminoheptane (1-methyl-hexylamine, 2-heptylamine). Primarily used as a nasal decongestant drug it has been considered relevant for sports drug testing due to its stimulating properties. A confirmatory gas chromatographic-mass spectrometric procedure was developed including liquid–liquid extraction and imine formation of tuaminoheptane employing various aldehydes and ketones such as formaldehyde, acetaldehyde, benzaldehyde and acetone. Extraction and derivatisation conditions were optimised for utmost efficiency and characteristic fragment ions obtained after electron ionisation allowed for a sensitive and selective analytical assay, which was validated with regard to recovery (50%), lower limit of detection (20 ng mL−1) as well as interday- and intraday precision (< 15%). The applicability to authentic urine samples was demonstrated using administration study specimens obtained from two male persons using Rhinofluimucil (tuaminoheptane hemisulfate) for intranasal application. The administered drug was detected up to 46h after repeated topical instillation of a total of approximately 3 mg.

scholarly journals Quantitative determination of major nandrolone metabolite in human urine by gas chromatography/mass spectrometry

2019 ◽  
pp. 78-85
Author(s):  
Pavel G. Shahoika ◽  
Aliaksandr A. Ahabalayeu ◽  
Olga N. Tchekhovskaya ◽  
Yury G. Pakhadnia ◽  
Sergey A. Beliaev ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Human Urine ◽  
Internal Standard ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Liquid Liquid Extraction ◽  
Validation Parameters ◽  
Limit Of Quantitation ◽  
World Anti Doping Agency

Nandrolone is an anabolic androgenic steroid. The use of this substance is prohibited by World Anti-Doping Agency (WADA). In National Anti-Doping Laboratory, we have developed method for quantitative determination of major nandrolone metabolite – 19-norandrosterone in human urine by GC/MS technique (Agilent 7000). Proposed method includes sample preparation of urine samples with enzymatic hydrolysis, liquid-liquid extraction followed by derivatization step with MSTFA. Deuterated 19-norandrosterone has been used as internal standard. Total run time comprised 16 min. Lower limit of quantitation accounted for 1 ng/mL. Spiked urine samples were prepared by mixing blank urine with standard solutions of 19-norandrosterone in range 1–30 ng/mL, correlation coefficient larger than 0.99. Method was verified to following validation parameters: selectivity, linearity, repeatability, accuracy, matrix effect, stability and robustness. Furthermore, measurement uncertainty was estimated. Thus, proposed method is able to detect threshold 19-norandrosterone in human urine and carry out its quantitation conforming WADA requirements.

scholarly journals Determination of Atenolol and Trimetazidine in Pharmaceutical Tablets and Human Urine Using a High Performance Liquid Chromatography-Photo Diode Array Detection Method

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Walaa El-Alfy ◽  
Omnia A. Ismaiel ◽  
Magda Y. El-Mammli ◽  
Abdalla Shalaby
Keyword(s):  
Human Urine ◽  
Limit Of Detection ◽  
Pure Form ◽  
Urine Samples ◽  
Dihydrogen Phosphate ◽  
Simple Liquid ◽  
Pharmaceutical Tablets ◽  
Limit Of Quantitation ◽  
Precision And Accuracy

A simple RP-HPLC-PDA method for determination of atenolol (ATN) and trimetazidine (TMZ) in human urine and tablets has been developed. Analytes were separated on a Caltrex BI column (125× 4.0 mm, 5 μm) with 25mM potassium dihydrogen phosphate pH 3.3, methanol, and acetonitrile mobile phases. The PDA detector was operated at 210 nm for TMZ and 225 nm for ATN and the flow rate was 1.0 mL/ min. Linearity was obtained over a concentration range of (1.0-100 μg/mL) for both analytes in standard solutions and the method was successfully applied for determination of target analytes in their pharmaceutical tablets. Excellent linearity was also obtained over concentration ranges of (0.25-25 μg/mL) and (0.5-25 μg/mL) in human urine for TMZ and ATN, respectively. A simple liquid-liquid extraction was applied for urine sample clean-up and a gradient method was used for chromatographic separation. The lower limit of quantitation (LOQ) was 0.99 and 0.60 μg/mL for ATN and TMZ, respectively. The limit of detection (LOD) was 0.30 and 0.18 μg/mL for ATN and TMZ, respectively. Inter- and intraday precision and accuracy for ATN were within ±1.89% in pure form and within ±2.85% in urine samples. Inter- and intraday precision and accuracy for TMZ were within ± 3.99% in pure form and within ± 3.19% in urine samples.

scholarly journals Rapid and Sensitive Spectrophotometric Method for the Determination of the Trace Amount of Thallium (III) in Water and Urine Samples by New Oxidative Coupling Reaction

2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Naef Ghllab Saeed Al-Tayar ◽  
Anantharaman Shivakumar ◽  
Ashwinee Kumar Shresta ◽  
Avinash K. Gowda
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Urine Samples ◽  
Oxidative Coupling Reaction ◽  
Relative Standard ◽  
Student’S T

A very simple, sensitive and fairly selective direct spectrophotometric method is presented for the rapid determination of thallium(III) at trace level. The method is based on the oxidation of 2-hydrazono-3-methyl-2,3-dihydrobenzo[d]thiazole hydrochloride (MBTH) by thallium(III) in phosphoric acid medium to form a diazoniumcation, which couples immediately with 10,11-dihydro-5Hdibenzo[b,f]azepine (IDB) at room temperature giving a blue colored species having a maximum absorption at 660 nm. The reaction conditions and other important analytical parameters were optimized.The calibration curve was found to be linear over the range of 0.1-4 μg/mL with molar absorptivity of 4.5 × 104 L mol- cm-1 and Sandell’s sensitivity of 0.00454 μg cm-2. The relative standard deviation and limit of detection have been found to be 0.58% and 0.0147 μg/mL respectively. Almost all common anions and cations are found notto interfering in matrix level of the analytical process. The method has been successfully applied for the determination of thallium(III) in synthetic standard mixtures, water and human urine samples. The performance of proposed method was evaluated in terms of student’s t-test and variance ratio F-test, to find out the significance of proposed method over the reported methods.    

scholarly journals Determination of Sulpiride by Capillary Electrophoresis with End-Column Electrogenerated Chemiluminescence Detection

2002 ◽  
Vol 48 (7) ◽  
pp. 1049-1058 ◽  
Author(s):  
Jifeng Liu ◽  
Weidong Cao ◽  
Haibo Qiu ◽  
Xiuhua Sun ◽  
Xiurong Yang ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Human Plasma ◽  
Phosphate Buffer ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Fused Silica ◽  
Urine Samples ◽  
Electrogenerated Chemiluminescence ◽  
Driving Voltage

Abstract Background: Capillary electrophoresis (CE) with tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+]-electrogenerated chemiluminescence (ECL) detection is a promising method for clinical analysis. In this study, a method combining CE with Ru(bpy)32+ ECL (CE-ECL) detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for determination of sulpiride in human plasma or urine was evaluated. Methods: Sulpiride was separated by capillary zone electrophoresis in uncoated fused-silica capillaries [50 cm × 25 μm (i.d.)] filled with phosphate buffer (pH 8.0) and a driving voltage of +15 kV, with end-column Ru(bpy)32+ ECL detection. A platinum disc electrode was used as working electrode. Sulpiride in human plasma or urine samples (100 μL) was extracted by a double-step liquid-liquid extraction procedure, dried under nitrogen at 35 °C in a water bath, and reconstituted with 100 μL of filtered water. The extraction solvent was ethyl acetate–dichloromethane (5:1 by volume). Results: Under optimum conditions (pH 8.0 phosphate buffer, injection for 6 s at 10 kV, and +1.2 V as detection potential), separation of sulpiride was accomplished within 4 min. The calibration curve was linear over a concentration range of 0.05–25.0 μmol/L, and the limit of detection was 2.9 × 10−8 mol/L for sulpiride. Intra- and interday CVs for ECL intensities were &lt;6%. Extraction recoveries of sulpiride were 95.6–101% with CVs of 2.9–6.0%. The method was clinically validated for patient plasma and urine samples. Conclusions: CE combined with Ru(bpy)32+ ECL is reproducible, precise, selective, and enables the analysis of sulpiride in human plasma and urine. It thus is of value for rapid and efficient analysis of amine-containing analytes of clinical interest.

scholarly journals Determination of Nicotine in Libyan Smokers' Urine Compared with that of Nonsmokers using Reversed Phase – High Performance Liquid Chromatog-raphy (RP-HPLC)

2019 ◽  
Vol 34 (3) ◽  
pp. 172-180
Author(s):  
Galal Elmanfe ◽  
Suad K. Omar ◽  
Noreldin S.Y. Abdolla ◽  
Amna M. Hassan
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Cost Effective ◽  
High Performance Liquid Chromatog ◽  
Reversed Phase ◽  
Urine Samples ◽  
Average Value ◽  
Limit Of Quantitation ◽  
One Step

The aim of the present study was to evaluate the levels of nicotine in twenty urine samples taken from ten smokers and ten non-smokers in Libya. Each volunteer was required to complete a questionnaire before providing the urine sample. The evaluation of the nicotine concentrations was carried out by means of a simple, rapid, cost effective but reliable, one-step extraction technique-reversed-phase high-performance liquid chromatography which was developed and validated for this purpose. The criteria and factors taken into consideration for this evaluation and validation include the linearity, precision, accuracy, limit of detection, and limit of quantitation. The urine samples from the smokers presented nicotine concentrations in the range of 0.037-1.979 µg/ml, with an average of 0.663 µg/ml. The range of the nicotine concentrations in non-smokers, on the other hand, was from 0.017-1.331 g/ml, where 0.273 µg/ml is the average value. Statistical analyses show that the nicotine concentrations were very significant in the smoker samples in contrast with the nonsmoker samples

scholarly journals Determination of Amphetamine and Methamphetamine by Dispersive Liquid Phase Micro-extraction: A Novel Experimental Approach

2020 ◽  
Vol 14 (4) ◽  
pp. 253-262
Author(s):  
Daruish Badakhshan ◽  
◽  
Majid Ramezani ◽  
Keyword(s):  
Liquid Phase ◽  
High Performance ◽  
Experimental Approach ◽  
Limit Of Detection ◽  
Urine Samples ◽  
Detection Methods ◽  
Extraction Solvent ◽  
Array Detection ◽  
Solvent Volume

Background: A syringe to syringe dispersive liquid phase micro-extraction-floating organic drop was applied and used for the simultaneous extraction and pre-concentration of trace amounts of amphetamine (AMP) and methamphetamine (MAMP) in urine samples. The extracted analytes were determined by high performance liquid chromatography along with diode array detection. Methods: In this study, n-hexane was selected as the extraction solvent without the need to use dispersive solvent. The analytical parameters affecting the micro-extraction efficiency, including pH of sample solution, extraction solvent volume, the cycles of extraction and time of centrifugation were investigated and optimized by screening and optimization experimental design methods.  Results: Underoptimal conditions, the calibration curve had a linear range of 2-100 μg/L with the determination coefficient of R2=99.8 and R2=99.6 for AMP and MAMP, respectively. The limit of detection was 2 μg/L for AMP and MAMP, and the enrichment factor was 75 and 68 for AMP and MAMP, respectively.  Conclusion: This method is very simple, rapid and has been successfully used for pre-concentration and measurement of the analytes in urine samples, which is important to forensic studies.  

Development of Dispersive Liquid-Liquid Microextraction Procedure for Trace Determination of Malathion Pesticide in Urine Samples

2020 ◽  
Author(s):  
Maryam RAMIN ◽  
Monireh KHADEM ◽  
Fariborz OMIDI ◽  
Mehran POURHOSEIN ◽  
Farideh GOLBABAEI ◽  
...  
Keyword(s):  
Enrichment Factor ◽  
Human Urine ◽  
High Performance ◽  
Limit Of Detection ◽  
Urine Samples ◽  
Human Urine Samples ◽  
Extraction Solvent ◽  
Ultraviolet Detector ◽  
Relative Standard

Background: Measurement of pesticides in biological matrices is become a serious challenge for researches because of their very low concentration in different matrices. The aim of this study was to develop a new sample preparation method with high accuracy and validity, simplicity and short retention time for determination of malathion. Methods: Dispersive liquid-liquid micro-extraction (DLLME) technique coupled with high-performance liquid chromatography equipped with ultraviolet detector (HPLC-UV) developed for trace extraction and determination of malathion pesticide in human urine samples. This study was done in 2017 at Tehran University of Medical Sciences, Tehran, Iran. One variable at a time (OVAT) method was used to optimize parameters affecting the malathion extraction. Different parameters such as extraction solvent, disperser solvent, and volume of the extraction solvent, volume of the disperser solvent, centrifugation time and speed, salt addition, and sample pH were studied and optimized. Results: Under the optimized conditions, the limit of detection and enrichment factor of the method were 0.5 µg L-1 and 200, respectively. The calibration curve was linear in the concentration range of 2-250 µg L-1 . The relative standard deviation for six replicate experiments at 200 µg L-1 concentration was less than 3%. The relative recoveries of spiked urine samples were 96.3%, 101.7% and 97.3% at three different concentration levels of 50, 200 and 1000 µg L-1 , respectively. Conclusion: DLLME procedure was successfully developed for the extraction of malathion from human urine samples. Compared to other extraction techniques, the proposed procedure had some advantages such as shorter extraction time, better reproducibility, and higher enrichment factor.  

Point of Care Method for the Determination of Dabigatran in Urine Samples From Patients On Treatment.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2270-2270 ◽  
Author(s):  
Job Harenberg ◽  
Sandra Kraemer ◽  
Shanshan Du ◽  
Christina Giese ◽  
Roland Kraemer
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Patent Application ◽  
Plasma Concentrations ◽  
Urine Samples ◽  
Plasma Samples ◽  
Specific Patient ◽  
Cutoff Value ◽  
Healthy Persons

Abstract Abstract 2270 Dabigatran is effective and safe for prevention of thromboembolism in several indications at daily fixed doses not requiring laboratory dose adjustment. However, it may be necessary to determine its activity/concentration in specific patient populations by specific assays from plasma samples. A point of care (POC) method may offer advantages by providing immediate results to facilitate medical decisions for acute therapeutic interventions. Plasma and urine samples were taken from patients on treatment with 110mg or 150mg dabigatran bid (n=110) and healthy persons (n=144) after having given written informed consent. Dabigatran was purified from commercially available Pradaxa® and its purity was characterized by analytical methods and S2238 thrombin specific chromogenic substrate assay and Hemoclot assay containing dabigatran standards. The S2238 assay was also used for the determination of dabigatran in plasma samples of patients and healthy persons using one purified dabigatran as standard. The lower limit of detection was 0.06μg/ml plasma. In urine dabigatran was determined by a POC method incubating the lyophilized reagents on mini-strips followed by incubation with patient‘s urine (international patent application No PCT/EP2012/002540). The development of colour of urine samples was determined 10 min after incubation with reagents quantitatively by optical density (OD) measurement and qualitatively as judged by eye according negative and positive colour (three independent readings by SD, SK, CG, and photographic documentation). To determine the positive and negative predictive value (PPV and NPV) of plasma samples, a cutoff value of <0.06μg/ml dabigatran was defined. The PPV and NPV of POC method was determined for urine samples of the control and treatment group according positive and negative development of colour as judged by eye reading. Control persons (n=144) displayed plasma concentrations of 0.04+0.03 μg/ml (mean, standard deviation) of whom 128 had values below the cutoff value <0.06 μg/ml. Sixteen patients had values above this cutoff. Accordingly, the NPV for correct negative results in controls was 88.9%. In patients on therapy the concentration of dabigatran was 0.12+0.08 μg/ml (n=107). 102/107 patients had plasma concentrations of dabigatran above the cutoff value of 0.06 μg/ml and 5 patients below the cutoff-value. This results in a PPV of 95.4%. Using the POC method for dabigatran in urine all of 144 control persons had negative values with OD measurement (0.803+0.116 OD units) and eye measurement. The NPV for control persons was 100%. During therapy with dabigatran, all 110 patients had positive colour development as judged by eye corresponding to an OD of 0.219+0.161. Accordingly, the PPV was 100% for patients on treatment with dabigatran. Limitations of the POC methods are the lack of information about the compliance of the patient and severe renal impairment. The validation of the POC assay by patients is ongoing. The POC method of patients on treatment with dabigatran improves the NPV and PPV from about 90% with plasma samples to 100% using urine samples, respectively. The method is non-invasive, rapid, and specific, can be repeatedly performed and may be used by medical personal and patients. The development of colour is different from the POC method for rivaroxaban. Disclosures: No relevant conflicts of interest to declare.

Liquid–liquid extraction and cloud point extraction for spectrophotometric determination of vanadium using 4-(2-pyridylazo)resorcinol

2015 ◽  
Vol 69 (4) ◽  
Author(s):  
Teodora S. Stefanova ◽  
Kiril K. Simitchiev ◽  
Kiril B. Gavazov
Keyword(s):  
Cloud Point ◽  
Spectrophotometric Determination ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Optimal Conditions ◽  
Liquid Liquid Extraction ◽  
Relative Standard

AbstractLiquid-liquid extraction (LLE) and cloud point extraction (CPE) of vanadium(V) ternary complexes with 4-(2-pyridylazo)resorcinol (PAR) and 2,3,5-triphenyl-2H-tetrazolum chloride (TTC) were investigated. The optimal conditions for vanadium extraction and spectrophotometric determination were identified. The composition (V : PAR : TTC) of the extracted species was 1 : 2 : 3 (optimal conditions; LLE), 2 : 2 : 2 (low reagents concentrations; LLE), 1 : 1 : 1 (short heating time; CPE), and 1 : 1 : 1 + 1 : 1 : 0 (optimal extraction conditions; CPE). LLE, performed in the presence of 1,2-diaminocyclohexane-N,N,N’,N’-tetraacetic acid and NH4F as masking agents, afforded the sensitive, selective, precise, and inexpensive spectrophotometric determination of vanadium. The absorption maximum, molar absorptivity, limit of detection, and linear working range were 559 nm, 1.95 × 105 dm3 mol−1 cm−1, 0.7 ng cm−3, and 2.2-510 ng cm−3, respectively. The procedure thus developed was applied to the analysis of drinking waters and steels. The relative standard deviations for V(V) determination were below 9.4 % (4-6 × 10−7 mass %; water samples) and 2.12 % (1-3 mass %; steel samples).

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