scholarly journals Determination of Clenbuterol Residues in Bovine Urine by Optical Immunobiosensor Assay

2001 ◽  
Vol 84 (4) ◽  
pp. 1025-1030 ◽  
Author(s):  
Simon A Haughey ◽  
G Andrew Baxter ◽  
Christopher T Elliott ◽  
Bjorn Persson ◽  
Carin Jonson ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Extraction Procedure ◽  
Cross Reactivity ◽  
Urine Samples ◽  
Farm Animals ◽  
Gas Chromatography Mass Spectrometry ◽  
Bovine Urine ◽  
Adrenoceptor Agonist ◽  
Simple Extraction ◽  
Working Day

Abstract Clenbuterol (CBL) is an orally active β2-adrenoceptor agonist which has been used in veterinary medicine as a broncodilator and an agent of uterine relaxation. It has however become better known as a drug used illegally to promote growth in farm animals. A rapid an sensitive biosensor assay was developed to detect CBL residues in bovine urine. The method involved a simple extraction procedure using tert-butyl methyl ether followed by analysis on the biosensor with results obtained against a buffer calibration curve. The assay allowed up to 88 samples to be analyzed per working day, with each cycle on the biosensor taking approximately 7 min to complete. The limit of detection (LOD) was determined as 0.27 ng/mL using 20 EU reference blank urine samples. The intra-assay Sr ranged from 4.7–7.6% for 3 control samples while the interassay Sr ranged from 9.2–12.7%. The recovery was found to be approximately 95%. A series of incurred urine samples were assayed and the results compared by Enzyme immunoassay (EIA), radio-immunoassay (RIA), and gas chromatography/mass spectrometry (GC/MS) analysis.Urine samples taken from local abattoirs were also analyzed by the biosensor method and by EIA analysis. The antibody used in the biosensor test exhibited high cross reactivity with at least 7 other β-agonists allowing detection of these compounds at less than 1 ng/mL in bovine urine.

Kavain Interference with Amphetamine Immunoassay

2020 ◽  
Author(s):  
H Madhavaram ◽  
T Patel ◽  
C Kyle
Keyword(s):  
False Positive ◽  
Cross Reactivity ◽  
Drug Prevention ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Piper Methysticum ◽  
Fragmentation Pattern ◽  
Aboriginal Communities ◽  
Australian Aboriginal ◽  
Positive Urine

Abstract We encountered unexpected false-positive urine results in three patients for amphetamine-type substances by immunoassay (IA), measured as part of community drug prevention programs. Kavain was identified in all three urine samples by gas chromatography-mass spectrometry (GC-MS). No other potential cross-reactants were found. Kavain is a kava-lactone present in kava, a ceremonial and recreational drink derived from the roots and stems of the plant Piper methysticum. It is consumed regularly by many indigenous Pacific and Australian Aboriginal communities. Urine IA was performed on a Beckman Coulter AU480 Analyzer using cloned enzyme donor immunoassay (CEDIA) amphetamine-type substance reagent and DRI ethanol reagent. We purchased three different kava powders from local kava clubs and dissolved in ethanol, then evaporated and reconstituted in blank urine and analyzed by IA, GC-MS for amphetamine-type substances. Additionally, authentic kavain standard was also tested for cross-reactivity by IA and analyzed by GC-MS to compare the mass fragmentation pattern and retention time with the kava powder and patient specimens. The patient urine samples tested positive by CEDIA IA for amphetamines. However, when analyzed by GC-MS, they were negative for amphetamine-type but contained kavain. The kava powders and kavain standard all cross-reacted with the amphetamine IA to give falsely detected results. GC-MS did not identify any amphetamine-type compounds in any of the kava powders nor in the kavain standard. To our knowledge, this is the first report of false-positive amphetamine measurements due to kavain, a component of the kava drink, widely consumed in Oceania and Australasia.

scholarly journals Development and Validation of a GC-MS Method for the Detection and Quantification of Clotiapine in Blood and Urine Specimens and Application to a Postmortem Case

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giulio Mannocchi ◽  
Flaminia Pantano ◽  
Roberta Tittarelli ◽  
Miriam Catanese ◽  
Federica Umani Ronchi ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Published Data ◽  
Limit Of Quantification ◽  
Blood And Urine Samples ◽  
Development And Validation ◽  
Urine Specimens ◽  
Detection And Quantification

Introduction. Clotiapine is an atypical antipsychotic of the dibenzothiazepine class introduced in a few European countries since 1970, efficient in treatment-resistant schizophrenic patients. There is little published data on the therapeutic and toxic concentrations of this drug.Aims. The aim of the present study is the development and validation of a method that allows the detection and quantification of clotiapine in blood and urine specimens by gas chromatography-mass spectrometry (GC-MS).Methods. Validation was performed working on spiked postmortem blood and urine samples. Samples were extracted with liquid-liquid extraction (LLE) technique at pH 8.5 with n-hexane/dichloromethane (85/15 v/v) and analysis was followed by GC-MS. Methadone-d9 was used as internal standard.Results. The limit of detection (LOD) was 1.2 and 1.3 ng/mL for urine and blood, respectively, while the lower limit of quantification (LLOQ) was 3.9 and 4.3 ng/mL, respectively. Linearity, precision, selectivity, accuracy, and recovery were also determined. The method was applied to a postmortem case. The blood and urine clotiapine concentrations were 1.32 and 0.49 μg/mL, respectively.Conclusions. A reliable GC-MS method for the detection and quantification of clotiapine in blood and urine samples has been developed and fully validated and then applied to a postmortem case.

scholarly journals Development of an Immunoassay for the Detection of Amyloid Beta 1-42 and Its Application in Urine Samples

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Anurak Wongta ◽  
Surat Hongsibsong ◽  
Somporn Chantara ◽  
Mookda Pattarawarapan ◽  
Ratana Sapbamrer ◽  
...  
Keyword(s):  
Amyloid Beta ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inexpensive Method ◽  
Amyloid Beta Peptides ◽  
Beta Peptides ◽  
The Cross ◽  
Sequence Similarities

Amyloid beta peptides (Aβ1-42) have been found to be associated with the cause of Alzheimer’s disease (AD) and dementia. Currently, methods for detecting Aβ1-42 are complicated and expensive. The present study is aimed at developing an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) to detect Aβ1-42 by using a polyclonal antibody from alpaca, an application used in urine samples. The serum was collected from the alpaca after immunizing it with Aβ1-42 at 500 μg/injection 5 times. The ic-ELISA was developed and showed a half-maximal inhibitory concentration ( I C 50 ) of 103.20 ng/ml. The limit of detection (LOD) was 0.39 ng/100 μl. The cross-reactivity was tested with Aβ1-40 and 8 synthesized peptides that had sequence similarities to parts of Aβ1-42. The cross-reactivity of Aβ1-40 and peptide 1 (DAEFRHDSGYE) was 55% and 69.4%, respectively. The ic-ELISA was applied to analyze Aβ1-42 in the urine and precipitated protein urine samples. This method can be used for detecting a normal level of total soluble Aβ (approximately 1 ng in 5 mg of precipitated urine protein) and can be used for detecting the early stages of AD. It is considered to be an easy and inexpensive method for monitoring and diagnosing AD.

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 <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.

Analytical Detection of Novel Stimulants by Immunoassay and Liquid Chromatography–High Resolution Mass Spectrometry: Case Studies on Ethylphenidate and Mephedrone

2020 ◽  
Author(s):  
Sarah L Belsey ◽  
Robert J Flanagan
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Limit Of Detection ◽  
False Negative ◽  
Cross Reactivity ◽  
Urine Samples ◽  
High Resolution Mass ◽  
Resolution Mass

Abstract The advent of hundreds of new compounds aimed at the substance misuse market has posed new analytical challenges. A semi-quantitative liquid chromatography–high resolution mass spectrometry (LC–HRMS) method has been developed to detect exposure to two novel stimulants, mephedrone and ethylphenidate, and selected metabolites. Centrifuged urine (50 µL) was diluted with LC eluent containing internal standards (mephedrone-d3, methylphenidate-d9, and ritalinic acid-d10, all 0.02 mg/L) (450 µL). Intra- and inter-assay accuracy and precision were within ± 15% and < 6% respectively, for all analytes. The limit of detection was 0.01 mg/L all analytes. Urine samples from mephedrone and ethylphenidate users were analyzed using immunoassay (amphetamine-group CEDIA) and LC–HRMS. Ethylphenidate, mephedrone, and selected metabolites all had low cross-reactivity (<1%) with the immunoassay. The median (range) amphetamine-group CEDIA concentration in urine samples from mephedrone users (N = 11) was 0.30 (<0.041–3.04) mg/L, with only one sample giving a positive CEDIA result. The amphetamine-group CEDIA concentration in the urine sample from an ethylphenidate user was <0.041 mg/L. Improving the detection of novel compounds is of increasing importance to enable accurate diagnosis and treatment. Immunoassay methods used for drug screening may be inappropriate and lead to false negative results. Conversely, detection of these compounds is possible through use of LC–HRMS and can provide information on the metabolites present after exposure to these drugs.

Consumption Of The Sugar Substitute Stevia Leads To Cross-Reactivity Of CEDIA® Buprenorphine II Immunoassay

2020 ◽  
Author(s):  
Sabine Plattner ◽  
Marion Pavlic ◽  
Florian Pitterl ◽  
Birthe Schubert
Keyword(s):  
Mass Spectrometry ◽  
Food Additives ◽  
German Society ◽  
Cross Reactivity ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometry Method ◽  
Mass Spectrometry Method ◽  
Sugar Substitute ◽  
Liquid Chromatography Tandem Mass

Abstract Buprenorphine is a semi-synthetic opioid which is often used in opiate maintenance therapy. For this purpose, regular toxicological analyses of urine samples are mandatory. For fast analytical results, analyses are commonly performed by immunoassay, e.g. Thermo Scientific™ CEDIA® Buprenorphine or Buprenorphine II assay. One drawback of immunoassay-based methods are possible cross-reactions with other substances. Several structural related and unrelated drugs have already been checked for cross-reactivity to CEDIA® Buprenorphine II immunoassay. In contrast, cross-reactivities have not been checked for any food additives. In the present study, a cross-reaction of CEDIA® Buprenorphine II assay to steviol glucuronide was investigated. Steviol glucuronide is a phase II metabolite of the sugar substitute Stevia. For our study, 32 urine samples of patients in rehabilitation centers were collected. These samples tested positive with the CEDIA® Buprenorphine II immunoassay. These findings were suspicious, since it was highly unlikely that the patients in those institutions had access to buprenorphine. The absence or presence of buprenorphine in urine samples was evaluated by a validated gas chromatography mass spectrometry method. In order to determine the concentration of steviol glucuronide in urine samples, a liquid chromatography-tandem mass spectrometry method has been developed and fully validated according to the respective guidelines of the German Society of the Toxicological and Forensic Chemistry. Cross-reactivity of steviol glucuronide in the CEDIA® Buprenorphine II immunoassay was observed at concentrations above 15000 µg/L. These findings demonstrate that food additives should also be considered as compounds that may reduce the selectivity of immunoassays. This places emphasis on the importance of confirming implausible results by selective analytical methods.

scholarly journals Determination of Pantothenic Acid in Foods by Optical Biosensor Immunoassay

2005 ◽  
Vol 88 (4) ◽  
pp. 1008-1014 ◽  
Author(s):  
Simon A Haughey ◽  
Anthony A O'Kane ◽  
G Andrew Baxter ◽  
Andras Kalman ◽  
Marie-José Trisconi ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Extraction Procedure ◽  
Pantothenic Acid ◽  
Optical Biosensor ◽  
Liquid Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Wide Range ◽  
Simple Extraction ◽  
Reference Samples

Abstract An optical biosensor inhibition immunoassay was developed using a specific pantothenic acid-binding protein for the quantitation of free pantothenic acid (vitamin B5) in foodstuffs. Samples were prepared by a simple extraction procedure in buffer, and vitamin content was estimated against authentic calibrants in the same buffer. Performance parameters included a working range of 10–5000 ng/mL, a limit of detection of 4.4 ng/mL, precision relative standard deviation of 5.4–7.1% over a range of concentrations, and recoveries >95% in the matrixes tested. A wide range of foodstuffs, including National Institute of Standards and Technology reference samples, were tested in 3 independent laboratories and the results were compared with microbiological assay and liquid chromatography/mass spectrometry (LC/MS) methods. The results indicate that the biosensor technique is appropriate for the estimation of pantothenic acid in a wide range of foodstuffs.

RADIOIMMUNOASSAY FOR PLASMA ANTIDIURETIC HORMONE

1972 ◽  
Vol 52 (1) ◽  
pp. 69-78 ◽  
Author(s):  
C. I. JOHNSTON
Keyword(s):  
Antidiuretic Hormone ◽  
Blood Volume ◽  
Plasma Levels ◽  
Extraction Procedure ◽  
Cross Reactivity ◽  
Arterial Blood ◽  
Harvesting Technique ◽  
Lysine Vasopressin ◽  
Simple Extraction ◽  
The Mean

SUMMARY Antibodies to [8-lysine]-vasopressin (LVP) were produced in rabbits by a macrophage harvesting technique. Using these antibodies a radioimmunoassay for vasopressin was established using LVP as standard and for labelling with 125I. The antibody demonstrated complete cross-reactivity to [8-arginine]- and [8-ornithine]-vasopressin but concentrations of oxytocin 1000 times greater caused no displacement. A simple extraction procedure for antidiuretic hormone (ADH) in plasma is described. Employing this extraction procedure followed by radioimmunoassay, plasma levels of ADH were measured in sheep. The mean level of plasma ADH in nine sheep was found to be 5·28 ± 1·18 in arterial blood and this rose to 21·04 ± 7·29 μu./ml after haemorrhage of 10 to 20% of their blood volume.

scholarly journals Validation of Screening Method for Residues of Diethylstilbestrol, Dienestrol, Hexestrol, and Zeranol in Bovine Urine Using Immunoaffinity Chromatography and Gas Chromatography/Mass Spectrometry

2003 ◽  
Vol 86 (4) ◽  
pp. 631-639 ◽  
Author(s):  
Leslie C Dickson ◽  
James D MacNeil ◽  
JoAnn Reid ◽  
Adrian C E Fesser
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Screening Method ◽  
Immunoaffinity Chromatography ◽  
Cross Reactivity ◽  
Gas Chromatography Mass Spectrometry ◽  
Bovine Urine ◽  
Chromatography Mass Spectrometry ◽  
Detection Capabilities ◽  
Growth Promotants

Abstract A method was developed, using commercially available immunoaffinity chromatography cleanup cartridges, followed by detection by gas chromatography/mass spectrometry, to screen for residues of the hormone growth promotants diethylstilbestrol, dienestrol, hexestrol, and zeranol in bovine urine. The single-laboratory, in-house validation included assessment of recoveries, repeatability, linearity of response, detection capability, and specificity (cross-reactivity) with a suite of antibiotics and other hormonal growth promotants. The method was validated for screening at a target concentration of 2.0 μg/L in urine. The detection capabilities for the analytes were diethylstilbestrol, 0.24; dienestrol, 0.15; hexestrol, 0.84; and zeranol, 0.28 μg/L.

scholarly journals A simplified approach for determination of urinary ethyl glucuronide by gas chromatography–mass spectrometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shayani Ghosh ◽  
Raka Jain ◽  
Satpal Singh ◽  
Ravindra Rao ◽  
Ashwani Kumar Mishra ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Urine ◽  
Impact Ionization ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Ethyl Glucuronide ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry

AbstractUrinary ethyl glucuronide (EtG), an alcohol biomarker, plays an essential role in monitoring alcohol abstinence and relapse during treatment for alcohol dependence. Detection of this biomarker has become a routine in many clinical and forensic laboratories over the last few years. Most previously published methods commonly use hyphenated chromatographic techniques along with extensive extraction procedure before analysis. This work aimed to develop and validate an electron impact ionization mode gas chromatography–mass spectrometry method to measure ethyl glucuronide levels in human urine. For its determination, urine samples were dried under a gentle stream of nitrogen, derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide, incubated, and injected into the instrument. The analysis was performed using single quadrupole gas chromatography–mass spectrometry (GC-MS) technology and validation was performed according to the guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh). The linearity of urinary EtG was obtained in the range of 30–5000 ng/ml with a correlation coefficient (r) above 0.999. The extraction recoveries exceeded 80%, and the obtained inter-day and intra-day precisions were below 15%. The achieved limit of detection was 10 ng/ml and limit of quantification achieved was 30 ng/ml. The electron ionization gas chromatography–mass spectrometry technique proves to be a feasible option for determining EtG in human urine when other sophisticated techniques are unapproachable. This method provides a good sensitivity and proves to be cost-effective, robust, and advantageous for both clinical as well as forensic settings.

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