Quantitative Confirmation of Dimethoate Residues in Wheat Plants by Single Ion Mass Spectrometry

1979 ◽  
Vol 62 (4) ◽  
pp. 782-785
Author(s):  
Young W Lee ◽  
Neil D Westcott
Keyword(s):  
Mass Spectrometry ◽  
Internal Standard ◽  
Wheat Plant ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Plant Sample ◽  
Minimum Detectable Concentration ◽  
Mass Spectrometric Method ◽  
Base Peak ◽  
Detectable Concentration

Abstract A gas chromatographic-single ion mass spectrometric method was developed for determining dimethoate residues in wheat plants. The base peak (m/e 87) of dimethoate was chosen as the single ion peak, and methyl stearate was used as an internal standard for this analysis. The minimum detectable concentration of dimethoate by this method was about 0.1 ppm for a 20 g wheat plant sample. The recoveries of dimethoate were about 89% at 0.13 ppm and >96% at 0.5-1 ppm.

The determination of acetone using mass spectrometry after acid hydrolysis of polymer acetals

1983 ◽  
Vol 48 (7) ◽  
pp. 2015-2020 ◽  
Author(s):  
Slavko Hudeček ◽  
Jaroslava Otoupalová ◽  
Miroslav Ryska ◽  
Jan Světlík ◽  
Pavel Čefelín
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Determination ◽  
Methyl Methacrylate ◽  
Acid Hydrolysis ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Hydrolysis Of

A mass spectrometric method for the determination of acetone in the presence of polymers has been suggested. Perdeuterated acetone was used as the internal standard. The method was employed in a quantitative determination of (2,2-dimethyl-1,3-dioxolane-4-yl) methyl methacrylate units in copolymers with methyl methacrylate and in the determination of copolymerization parameters.

Pregnanediol-3 alpha-glucuronide measured in diluted urine by mass spectrometry with fast atom bombardment/negative-ion ionization.

1985 ◽  
Vol 31 (1) ◽  
pp. 46-49 ◽  
Author(s):  
G Moneti ◽  
G Agati ◽  
M G Giovannini ◽  
M Pazzagli ◽  
R Salerno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Ionization Technique ◽  
Fast Atom Bombardment Ionization ◽  
Negative Ion Mode

Abstract We describe a mass-spectrometric method based on the fast atom bombardment ionization technique in the negative-ion mode for measuring pregnanediol-3 alpha-glucuronide in diluted urine from women. The procedure requires addition of testosterone-17 beta-D-glucuronide (2.5 micrograms/25 microL) to the urine sample as internal standard, and the sample is added directly to the fast atom bombardment target with no further manipulation. We have assessed and evaluated the method by the traditional criteria of reliability.

scholarly journals Microprobe two-step laser mass spectrometry as an analytical tool for meteoritic samples

1997 ◽  
Vol 178 ◽  
pp. 305-320 ◽  
Author(s):  
Simon J. Clemett ◽  
Richard N. Zare
Keyword(s):  
Mass Spectrometry ◽  
Rapid Heating ◽  
Multiphoton Ionization ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Spectrometric Analysis ◽  
Laser Mass Spectrometry ◽  
Mass Spectrometric Method ◽  
Complex Materials ◽  
Spot Area

Microprobe two-step laser mass spectrometry (μL2MS) is a new mass spectrometric method in which the two essential steps of any mass spectrometric analysis, vaporization and ionization, are carried out using two independent laser sources. In the first step, the output of a pulsed infrared laser is focused on the sample to cause rapid heating in the spot area illuminated, which is typically 40 μm by 40 μm. In the second step, the output of a pulsed ultraviolet laser causes (1+1) resonance-enhanced multiphoton ionization (REMPI) of those desorbed neutral molecules that (1) are able to absorb this UV wavelength and (2) whose ionization potential is less than the energy of two photons of this UV wavelength. The resulting ions are then mass analyzed in a reflectron time-of-flight apparatus. Under suitable conditions fragmentation can be avoided in both the vaporization and ionization steps so that μL2MS can be applied to the analysis of a mixture of molecules. Applications of μL2MS to meteorite samples are presented as a means of detecting trace amounts of certain organic molecules present in complex materials without prior sample preparation, extraction, purification, and separation steps. Moreover, this analysis can be carried out with micrometer spatial resolution so that in favorable cases the presence or absence of certain molecules can be correlated to mineralogical features of the sample.

Ultra-Performance Liquid Chromatography Coupled with a Triple Quadrupole Mass Spectrometric Method for the Quantification of Anti-epileptic drugs Methsuximide and Normesuximide in Human Plasma and its Application in a Pharmacokinetic Study

2021 ◽  
Vol 17 ◽  
Author(s):  
Karthik Rajendran ◽  
Karthika Anoop ◽  
Krishnaveni Nagappan ◽  
Genguchetti Mohan Sekar ◽  
Sankham Devendran Rajendran
Keyword(s):  
Human Plasma ◽  
Pharmacokinetic Study ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Current Method ◽  
Ultra Performance Liquid Chromatography ◽  
Mass Spectrometric ◽  
Therapeutic Drug ◽  
Spectrometric Method ◽  
Mass Spectrometric Method

Background: Extensive therapeutic drug monitoring needs an analytical method for efficient and sensitive quantification of analytes of interest in clinical pharmacology. Objective: A rapid, robust, sensitive and simple UPLC-MS/MS method to quantify Methsuximide (Ms) and N-desmethyl methsuximide/Normesuximide (MsMET) in human plasma was optimized, developed, and validated for application in a pharmacokinetic study. Method: Reverse phased chromatography was performed using Zorbax SB-C18, 4.6 x 75 mm., 3.5 µm as stationary phase, methanol and 0.1% formic acid (60:40 v/v) as mobile phase which was delivered isocratically at a flow rate of 0.9 mL/min. The sample injection volume was 5 µL. Mass spectrometric quantification of the analytes was performed using positive electrospray ionization as mass interface along with multiple reaction monitoring (MRM) as acquisition mode. Results: The selected mass transition ions for analyte, metabolite and its respective internal standards are as follows, precursor ion (m/z) and product ion (m/z): Ms (204.06 and 119.02), MsMET (190.05 and 119.82), Ms internal standard (MsIS) (209.17 and 124.02), and MsMET internal standard (MsMETIS) (195.09 and 124.16), respectively. The current method was found to be linear for Ms (60.72-5920 ng/mL) and MsMET (60.38-6010 ng/mL) with r2 values not less than 0.999. The mean recoveries of all analytes ranged between 71.37 and 86.38 percentage. Conclusion: This method was validated in accordance with USFDA’s bioanalytical guidelines. This method could be applied for a routine analysis of Ms and MsMET in clinical pharmacological practice.

scholarly journals Rapid, Sensitive and Validated Ultra-Performance Liquid Chromatography/Mass Spectrometric Method for the Determination of Fenofibric Acid and its Application to Human Pharmacokinetic Study

2010 ◽  
Vol 7 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Sunil K. Dubey ◽  
Manoj S. Tomar ◽  
Anil Kumar Patni ◽  
Arshad Khuroo ◽  
Simrit Reyar ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Negative Ions ◽  
Ultra Performance Liquid Chromatography ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Good Precision ◽  
Mass Spectrometric Method ◽  
Fenofibric Acid

The first, rapid and sensitive ultra performance liquid chromatography mass spectrometric method for the determination of fenofibric acid, the active metabolite of fenofibrate, a lipid regulating agent, in human EDTA plasma has been developed and validated using fenofibric d6 acid as internal standard and Waters LC-MS/MS. Negative ions of fenofibric acid and fenofibric d6 acid were detected in multiple reaction-monitoring (MRM) mode. The method was validated over a concentration range of 0.176 μg/mL to 19.837 μg/mL (r ≥ 0.99). It took only 1.5 minute to analyse a sample. Intra- and inter-run precision of fenofibric acid assay at four concentrations ranged from 0.5% to 4.3% with accuracy varied from 93.1 to 108.1% indicating good precision and accuracy. Analytical recoveries of fenofibric acid and internal standard in plasma were less than 90%. This method was successfully applied for evaluation of pharmacokinetics of fenofibric acid after a single oral dose of 145 mg fenofibrate to 10 Indian healthy volunteers

scholarly journals Development and Validation of a Liquid Chromatographic/Tandem Mass Spectrometric Method for Determination of Tetracycline in Human Plasma: Application to Bioequivalence Study

2008 ◽  
Vol 91 (4) ◽  
pp. 731-738 ◽  
Author(s):  
Liberato Brum ◽  
Ana Maria Pugens ◽  
Mariely Camila Pritsch ◽  
Patricia Bertuol Mantovani ◽  
Maurício Bedim dos Santos ◽  
...  
Keyword(s):  
Human Plasma ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic

Abstract A fast, sensitive, and specific liquid chromatographic/tandem mass spectrometric method was developed and validated for determination of tetracycline in human plasma. Tetracycline and oxytetracycline [internal standard (IS)] were extracted from the plasma by protein precipitation. The mobile phase consisted of acetonitrileformic acid 0.1 (48 + 52, v/v), run at a flow rate of 1 mL/min (split 1:5). Detection was performed by positive electrospray ionization in multiple reaction monitoring mode, monitoring the transitions 444.8 > 410.0 and 461.0 > 426.0 for tetracycline and IS, respectively. The analysis was performed in 3.5 min and the method was linear in the plasma concentration range of 506000 ng/mL. The mean extraction recoveries for tetracycline and IS from plasma were 92.14 and 94.04, respectively. Method validation investigated parameters such as the linearity, precision, accuracy, specificity, and stability, giving results within the acceptable range. The proposed method was successfully applied for determination of tetracycline in human plasma samples to support bioequivalence studies.

scholarly journals Mass spectrometric analysis of prenyl phosphates and their glycosylated forms.

1994 ◽  
Vol 41 (3) ◽  
pp. 345-349 ◽  
Author(s):  
B A Wolucka ◽  
E De Hoffmann
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Impact Ionization ◽  
Negative Ions ◽  
Mass Range ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Spectrometric Analysis ◽  
Tandem Mass ◽  
Mass Spectrometric Method

Three different mass spectrometric method suitable for the analysis of polyprenyl and dolichyl phosphates and their glycosylated forms are described. Fast atom bombardment mass spectrometry (FAB MS) of glycosyl monophosphopolyprenols produces negative ions characteristic of the intact molecule. Tandem mass spectrometry of (M-H)- anions allows the determination of masses of both glycosyl and lipid moieties. Thus, for example, FAB-MS/MS of a mixture of native glycosyl monophosphopolyprenols isolated from ethambutol-treated Mycobacterium smegmatis enabled us to detect two novel pentosyl monophosphopolyprenols. Two other methods are proposed for the analysis of prenyl phosphates, as these compounds do not produce fragments in FAB-MS/MS at low collisional energy. By Desorption Electron Impact ionization (DEI) an intense (M-H3PO4)+ ion as well as fragments corresponding to the successive loss of isoprene residues (68 Da) can be observed. Alternatively, Desorption Chemical Ionization yields ions corresponding to the loss of 66, 78 and 98 Da (i.e. of a part or the entire phosphate moiety) of a prenyl phosphate molecule. Tandem mass spectrometry of the (M-H-98)- ion gives a series of intense fragments differing by 68 mass units over the whole mass range.

scholarly journals Rapid determination of aminoglycosides in pharmaceutical preparations by electrospray ionization mass spectrometry

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Freneil B. Jariwala ◽  
John A. Hibbs ◽  
Iryna Zhuk ◽  
Svetlana A. Sukhishvili ◽  
Athula B. Attygalle
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Rapid Determination ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Mass Spectrometric Method

AbstractAminoglycosides are broad-spectrum antibiotics often employed to combat Gram-negative bacterial infections. A technique based on electrospray-ionization mass spectrometry (ESI-MS) was developed for rapid determination of aminoglycosides. This method, which does not require prior chromatographic separation, or derivatization and extensive sample preparation steps, was deployed to estimate gentamicin, tobramycin, and amikacin in pharmaceutical formulations. Upon gas-phase collisional activation, protonated gentamicin, tobramycin, and amikacin undergo a facile loss of their respective “C” ring moiety to produce characteristic ions of m/z 322, 324, and 425, respectively. The mass spectral peak intensities for these specific product ions were monitored either by a flow-injection analysis selected-ion monitoring (FIA-SIM) time-intensity method or by a mass spectrometric internal-standard method. The linear dynamic ranges of detection for both methods were evaluated to be 10–1000 ng/mL for gentamicin, 25–2500 ng/mL for tobramycin, and 10–1000 ng/mL for amikacin. The internal-standard mass spectrometric method afforded lower intra-day and inter-day variations (2.3–3.0% RSD) compared to those from FIA-SIM method (4.5–5.0% RSD). This method was applied as a potential alternative procedure to determine gentamicin in commercial pharmaceutical samples and to monitor the release of gentamicin from “self-defensive” tannic acid-based layer-by-layer films into phosphate buffer solutions at different pHs.

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