scholarly journals Development and Performance Evaluation of a Tandem Mass Spectrometry Assay for 4 Adrenal Steroids

2006 ◽  
Vol 52 (8) ◽  
pp. 1559-1567 ◽  
Author(s):  
Mark M Kushnir ◽  
Alan L Rockwood ◽  
William L Roberts ◽  
Elizabeth G Pattison ◽  
William E Owen ◽  
...  
Keyword(s):  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Sample Volume ◽  
Reference Intervals ◽  
Small Sample ◽  
Tandem Mass ◽  
Adrenal Steroids ◽  
Adult Males ◽  
Butyl Ether ◽  
Adrenal Steroid

Abstract Background: Congenital adrenal hyperplasia is a group of autosomal recessive disorders caused by a deficiency of 1 of 4 enzymes required for the synthesis of glucocorticoids, mineralocorticoids, and sex hormones. Analysis of 11-deoxycortisol (11DC), 17-hydroxyprogesterone (17OHP), 17-hydroxypregnenolone (17OHPr), and pregnenolone (Pr) in blood allows detection of these enzyme defects. Methods: The steroids were extracted from 200 μL of serum or plasma by solid-phase extraction, derivatized to form oximes, and extracted again with methyl t-butyl ether. Instrumental analysis was performed on an API 4000 tandem mass spectrometer with electrospray ionization in positive mode and multiple reaction-monitoring acquisition. Results: The limits of detection were 0.025 μg/L for 11DC, 17OHP, and Pr and 0.10 μg/L for 17OHPr. The method was linear to 100 μg/L for 11DC, 17OHP, and Pr, respectively, and to 40 μg/L for 17OHPr. Within- and between-run (total) imprecision (CVs) were <7.1% and 11%, respectively. Reference intervals for children in Tanner stages 1 through 5 and adult males and females for 17OHP, 11DC, Pr, and 17OHPr were established. Prepared samples were stable for >72 h. Conclusions: The detection limit and selectivity of this method and its small sample volume requirement allow analysis of endogenous concentrations of adrenal steroids in serum or plasma from children and adults. The method thus has an important potential role in the evaluation of the status of 4 of the enzymes involved in adrenal steroid biosynthesis.

scholarly journals Performance Characteristics of a Novel Tandem Mass Spectrometry Assay For Serum Testosterone

2006 ◽  
Vol 52 (1) ◽  
pp. 120-128 ◽  
Author(s):  
Mark M Kushnir ◽  
Alan L Rockwood ◽  
William L Roberts ◽  
Elizabeth G Pattison ◽  
Ashley M Bunker ◽  
...  
Keyword(s):  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Small Sample ◽  
Sex Hormone Binding Globulin ◽  
Methyl Tert Butyl Ether ◽  
Tandem Mass ◽  
Adult Males ◽  
Butyl Ether ◽  
Tandem Mass Spectrometric ◽  
Women And Children

Abstract Background: Commercial immunoassays for testosterone (Te) may give inaccurate results for samples from women and children, leading to misdiagnosis and inappropriate treatment. We developed a sensitive and specific tandem mass spectrometric assay for measurement of Te at the concentrations encountered in women and children. Methods: Te was extracted with methyl tert-butyl ether from 100 μL of serum or plasma, derivatized to form an oxime, and reextracted by solid-phase extraction. Instrumental analysis was performed on an API 4000 HPLC tandem mass spectrometer in the multiple-reaction monitoring (MRM) mode. The MRM transitions (m/z) were 304→124 and 304→112 for Te and 307→124 and 307→112 for d3-Te. Results: Within- and between-run CVs were <12% and 7.9%, respectively. The limit of quantification was 0.0346 nmol/L (1 ng/dL). Reference intervals for sex hormone–binding globulin and total, free, and bioavailable Te were established for children of Tanner stages 1 through 5 and adult males and females. Conclusions: The sensitivity and specificity of the method are adequate for analysis of Te in samples from women and children. The method requires small sample volumes, has adequate precision, and is not subject to interferences.

scholarly journals HPLC–Tandem Mass Spectrometric Method to Characterize Resveratrol Metabolism in Humans

2007 ◽  
Vol 53 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Mireia Urpi-Sarda ◽  
Raul Zamora-Ros ◽  
Rosa Lamuela-Raventos ◽  
Antonio Cherubini ◽  
Olga Jauregui ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Biological Effects ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Assessment Tools ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Tandem Mass Spectrometric

Abstract Background: Nutritional biomarkers are alternatives to traditional dietary assessment tools. We sought to develop a method for nutritional analysis of resveratrol, a phenolic compound with purported health-promoting properties, and to determine all resveratrol metabolites. Methods: We obtained LDL and urine samples from 11 healthy male volunteers who had consumed 250 mL of Merlot red wine. We measured resveratrol and its metabolites with 96-well solid-phase extraction plates coupled with HPLC-tandem mass spectrometry. Hexestrol was used as the internal standard. Gradient chromatography in multiple reaction monitoring mode was performed on a Luna C18 column, maintained at 40 °C; m/z transitions were as follows: resveratrol, 227/185; resveratrol glucosides, 389/227; resveratrol glucuronides, 403/227; resveratrol sulfates, 307/227; taxifolin, 303/285; and hexestrol, 269/134. Results: Standard calibration curves were linear at 4.4–3289.5 nmol/L. Residual analyses were 100% (3.2) for trans-resveratrol and 100% (11.1) for trans-piceid. In both matrices, imprecision (CV) was <10.8% at all concentrations. Detection limits for resveratrol were 0.2 nmol/L (LDL), 0.3 nmol/L (synthetic urine), and 4.0 nmol/L (blank urine). Resveratrol and metabolites were checked for stability, and no degradation was observed. Conclusions: The HPLC–tandem mass spectrometry method enabled us to identify resveratrol sulfates in human LDL and to characterize the complete profile of resveratrol metabolism in human LDL and urine. This method provides an accurate index of exposure to resveratrol and its metabolites, which can be used as nutritional biomarkers for evaluating the biological effects of moderate wine intake on human health.

A New Method Using Liquid Chromatography Tandem Mass Spectrometry to Detect NDMA in Water

2013 ◽  
Vol 742 ◽  
pp. 355-358
Author(s):  
Chao Jie Zhang ◽  
Geng Zhang ◽  
Lu Ting Chen ◽  
Qian Chen ◽  
Qi Zhou
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Tandem Mass ◽  
Reaction Monitoring ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Trace Concentrations

This study focused on using liquid Chromatography Tandem Mass Spectrometry to detect N-Nitrosodimethylamine (NDMA) at trace concentrations in water. The water sample was preconcentrated by solid-phase extraction method. To find an elution which can obtain higher recovery, three reagents with different organic solvents were examined. After comparing the recoveries and the standard deviation of the elution, finally the dichloromethane was determined as the elution of the experiment. Then the concentrated sample was analyzed by a method combining SPE pretreatment and LC separation with tandem mass spectrometry using multiple reaction monitoring (MRM).

Liquid-chromatographic analysis for cyclosporine with use of a microbore column and small sample volume.

1986 ◽  
Vol 32 (7) ◽  
pp. 1407-1409 ◽  
Author(s):  
T Annesley ◽  
K Matz ◽  
L Balogh ◽  
L Clayton ◽  
D Giacherio
Keyword(s):  
Chromatographic Analysis ◽  
Glass Tube ◽  
Sample Volume ◽  
Small Sample ◽  
Butyl Ether ◽  
Microbore Columns ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic ◽  
Microbore Column ◽  
Small Sample Volume

Abstract This liquid-chromatographic assay requires 0.2 to 0.5 mL of whole blood, avoids the use of diethyl ether, and consumes only 10 to 20% of the solvents used in prior methods. Sample preparation involves an acidic extraction with methyl-t-butyl ether, performed in a 13 X 100 mm disposable glass tube, then a short second extraction of the organic phase with sodium hydroxide. After evaporation of the methyl-t-butyl ether, chromatography is performed on an "Astec" 2.0-mm (i.d.) octyl column. We compared results by this procedure with those by use of earlier larger-scale extractions and their respective 4.6-mm (i.d.) columns; analytical recoveries of cyclosporins A and D were comparable with previous findings and results for patients' specimens were equivalent, but the microbore columns provided greatly increased resolution and sensitivity.

scholarly journals Free Thyroid Hormones in Serum by Direct Equilibrium Dialysis and Online Solid-Phase Extraction–Liquid Chromatography/Tandem Mass Spectrometry

2008 ◽  
Vol 54 (4) ◽  
pp. 642-651 ◽  
Author(s):  
Bingfang Yue ◽  
Alan L Rockwood ◽  
Tanya Sandrock ◽  
Sonia L La’ulu ◽  
Mark M Kushnir ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Equilibrium Dialysis ◽  
Reference Intervals ◽  
Tandem Mass ◽  
Phase Extraction ◽  
Online Solid Phase Extraction ◽  
Direct Immunoassay

Abstract Background: Measurements of free thyroxine (FT4) and free triiodothyronine (FT3) are important for the diagnosis and monitoring of thyroid diseases. Considerable differences among methods limit their clinical utility, however, and accurate methods are needed for various clinical specimens. We describe a direct equilibrium dialysis (ED)–liquid chromatography (LC)/tandem mass spectrometry (MS/MS) method for FT4 and FT3. Methods: ED was selected as the separation step. Serum samples were dialyzed 1:1 against a simple protein-free buffer for 20 h at 37 °C. Thyroid hormones in dialysates were purified by online solid-phase extraction (SPE), then chromatographically separated and quantified in positive ion and multiple reaction monitoring modes. Results: For FT4 and FT3, the lower and upper limits of quantification were 1 ng/L (pg/mL) and 400 ng/L with total imprecision <10%. The method correlated well with an ED-RIA, 2 direct immunoassay methods for FT4, and 1 direct immunoassay and 1 tracer dialysis method for FT3. The adult reference intervals were 12.8–22.2 ng/L for FT4 and 3.62–6.75 ng/L for FT3. Reference intervals for the second trimester of pregnancy (14–20 weeks of gestation) were also established. Conclusions: We developed a simple protein-free buffer and ED procedure. The performance characteristics and high throughput of the LC-MS/MS method with online SPE for FT4 and FT3 (also reverse T3) are sufficient for the intended clinical use.

Measurement of plasma vitamin K1 (phylloquinone) and K2 (menaquinones-4 and -7) using HPLC-tandem mass spectrometry

2016 ◽  
Vol 54 (7) ◽  
Author(s):  
Ineke J. Riphagen ◽  
Jan C. van der Molen ◽  
Martijn van Faassen ◽  
Gerjan Navis ◽  
Martin H. de Borst ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Quantitative Determination ◽  
Vitamin K ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Matrix Gla Protein ◽  
Plasma Vitamin ◽  
Tandem Mass

AbstractGiven the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin KWe used HPLC-tandem mass spectrometry with atmospheric pressure chemical ionization for measurement of plasma PK, MK-4, and MK-7. Solid-phase extraction was used for sample clean-up. Mass spectrometric detection was performed in multiple reaction monitoring mode. Functional vitamin K insufficiency was defined as plasma desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) >500 pmol/L.Lower limits of quantitation were 0.14 nmol/L for PK and MK-4 and 4.40 nmol/L for MK-7. Linearity up to 15 nmol/L was excellent. Mean recoveries were >92%. Fasting plasma PK concentration was associated with recent PK intake (ρ=0.41, p=0.002) and with plasma MK-4 (ρ=0.49, p<0.001). Plasma PK (ρ=0.38, p=0.003) and MK-4 (ρ=0.46, p<0.001) were strongly correlated with plasma triglyceride concentrations. Furthermore, we found that MK-4-triglyceride ratio, but not PK-triglyceride ratio, was significantly associated with functional vitamin K insufficiency (OR 0.22 [0.07–0.70], p=0.01) in RTR.The developed rapid and easy-to-use LC-MS/MS method for quantitative determination of PK, MK-4, and MK-7 in human plasma may be a good alternative for the labor-intensive and time-consuming LC-MS/MS methods and enables a higher sample throughput.

scholarly journals Confirmatory Determination of Six Penicillins in Honey by Liquid Chromatography/Electrospray Ionization–Tandem Mass Spectrometry

2004 ◽  
Vol 87 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Jian Wang
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Penicillin G ◽  
Tandem Mass ◽  
Ionization Tandem Mass Spectrometry

Abstract A confirmatory method for 6 penicillin antibiotics (amoxicillin, ampicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin) in honey is presented that allows determination and confirmation of identity of the antibiotics at trace levels. The method includes the use of a stable isotope-labeled internal standard benzyl (d7-phenyl) penicillate and removal of sugar and other substances by solvent and solid-phase extraction. The honey extracts are then analyzed for penicillin residues by liquid chromatography/electrospray ionization–tandem mass spectrometry. Mass spectral acquisition was achieved in an electrospray positive ion mode by applying multiple reaction monitoring of 2 or 3 fragment ion transitions to provide a high degree of sensitivity and specificity. Typical recoveries of 6 penicillins at fortification levels of 6, 16, 40, and 80 μg/kg ranged from 51.4 to 132.9%. The recoveries varied with the individual penicillins and were affected by different honey matrixes. The ion ratios were consistent and could be used for confirmation of identity of the penicillins. The method limits of detection (μg/kg) were 0.25 for amoxicillin, 0.19 for ampicillin, 0.068 for penicillin G, 0.028 for oxacillin, 0.052 for cloxacillin, and 0.085 for dicloxacillin. The method limits of confirmation (μg/kg) were 0.44 for amoxicillin, 0.52 for ampicillin, 0.23 for penicillin G, 0.14 for oxacillin, 0.14 for cloxacillin, and 0.15 for dicloxacillin when a sample size of 5 g honey was used.

Direct determination of plasma copper and zinc in infants by atomic absorption with discrete nebulization.

1981 ◽  
Vol 27 (8) ◽  
pp. 1445-1447 ◽  
Author(s):  
T Makino ◽  
K Takahara
Keyword(s):  
Atomic Absorption ◽  
Direct Determination ◽  
Absorption Spectrometry ◽  
Sample Volume ◽  
Reference Intervals ◽  
Small Sample ◽  
Time Saving ◽  
Copper And Zinc ◽  
Plasma Copper

Abstract A new micromethod for the determination of copper and zinc is presented. Sample volumes can be as little as 10 (Cu) and 20 (Zn) microliter of plasma or serum, by using discrete (small sample volume) nebulization in place of conventional nebulization in place of conventional nebulization in atomic absorption spectrometry. The present method has slightly poorer precision than the conventional nebulization method, but has the advantages of requiring commercially available apparatus without any modification, involving simple sample preparation, and being time-saving. Results agree well with those by the trichloroacetic acid deproteinization method. In addition, this method is useful for pediatric samples, and we report reference intervals for full-term and premature infants, as well as adults.

scholarly journals An open-source software analysis package for Microspheres with Ratiometric Barcode Lanthanide Encoding (MRBLEs)

2018 ◽  
Author(s):  
Björn Harink ◽  
Huy Nguyen ◽  
Kurt Thorn ◽  
Polly Fordyce
Keyword(s):  
Open Source ◽  
Solid Phase ◽  
Sample Volume ◽  
Small Sample ◽  
Fluorescent Material ◽  
Software Analysis ◽  
Peptide Motifs ◽  
Reduce Measurement Error ◽  
Analysis Package ◽  
Spectrally Encoded

AbstractMultiplexed bioassays, in which multiple analytes of interest are probed in parallel within a single small volume, have greatly accelerated the pace of biological discovery. Bead-based multiplexed bioassays have many technical advantages, including near solution-phase kinetics, small sample volume requirements, many within-assay replicates to reduce measurement error, and, for some bead materials, the ability to synthesize analytes directly on beads via solid-phase synthesis. To allow bead-based multiplexing, analytes can be synthesized on spectrally encoded beads with a 1:1 linkage between analyte identity and embedded codes. Bead-bound analyte libraries can then be pooled and incubated with a fluorescently-labeled macromolecule of interest, allowing downstream quantification of interactions between the macromolecule and all analytes simultaneously via imaging alone. Extracting quantitative binding data from these images poses several computational image processing challenges, requiring the ability to identify all beads in each image, quantify bound fluorescent material associated with each bead, and determine their embedded spectral code to reveal analyte identities. Here, we present a novel open-source Python software package (the mrbles analysis package) that provides the necessary tools to: (1) find encoded beads in a bright-field microscopy image; (2) quantify bound fluorescent material associated with bead perimeters; (3) identify embedded ratiometric spectral codes within beads; and (4) return data aggregated by embedded code and for each individual bead. We demonstrate the utility of this package by applying it towards analyzing data generated via multiplexed measurement of calcineurin protein binding to MRBLEs (Microspheres with Ratiometric Barcode Lanthanide Encoding) containing known and mutant binding peptide motifs. We anticipate that this flexible package should be applicable to a wide variety of assays, including simple bead or droplet finding analysis, quantification of binding to non-encoded beads, and analysis of multiplexed assays that use ratiometric, spectrally encoded beads.

scholarly journals Multiresidue antibiotic-metabolite quantification method using ultra-performance liquid chromatography coupled with tandem mass spectrometry for environmental and public exposure estimation

2021 ◽  
Vol 413 (23) ◽  
pp. 5901-5920
Author(s):  
Elizabeth Holton ◽  
Barbara Kasprzyk-Hordern
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Ultra Performance Liquid Chromatography ◽  
Weighting Factor ◽  
Tandem Mass ◽  
Instrumental Performance ◽  
Environmental Matrices

AbstractThis manuscript describes a new multiresidue method utilising ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) via multiple reaction monitoring (MRM), for the identification and quantification of 58 antibiotics and their 26 metabolites, in various solid and liquid environmental matrices. The method was designed with a ‘one health’ approach in mind requiring multidisciplinary and multisectoral collaborative efforts. It enables comprehensive evaluation of antibiotic usage in surveyed communities via wastewater-based epidemiology, as well as allowing for the assessment of potential environmental impacts. The instrumental performance was very good, demonstrating linearity up to 3000 μg L−1, and high accuracy and precision. The method accuracy in several compounds was significantly improved by dividing calibration curves into separate ranges. This was accompanied by applying a weighting factor (1/x). Microwave-assisted and/or solid-phase extraction of analytes from liquid and solid matrices provided good recoveries for most compounds, with only a few analytes underperforming. Method quantification limits were determined as low as 0.017 ng L−1 in river water, 0.044 ng L−1 in wastewater, 0.008 ng g−1 in river sediment, and 0.009 ng g−1 in suspended solids. Overall, the method was successfully validated for the quantification of 64 analytes extracted from aqueous samples, and 45 from solids. The analytes that underperformed are considered on a semi-quantitative basis, including aminoglycosides and carbapenems. The method was applied to both solid and liquid environmental matrices, whereby several antibiotics and their metabolites were quantified. The most notable antibiotic-metabolite pairs are three sulfonamides and their N-acetyl metabolites; four macrolides/lincomycins and their N-desmethyl metabolites; and five quinolone metabolites. Graphical abstract

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