scholarly journals Amnesic Shellfish Poisoning Toxins in Shellfish: Estimation of Uncertainty of Measurement for a Liquid Chromatography/Tandem Mass Spectrometry Method

2003 ◽  
Vol 86 (5) ◽  
pp. 1095-1100 ◽  
Author(s):  
Patrick T Holland ◽  
Paul McNabb ◽  
Andrew I Selwood ◽  
Tracey Neil
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Domoic Acid ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Tissue Homogenate ◽  
Uncertainty Of Measurement ◽  
Shellfish Poisoning ◽  
Total Uncertainty ◽  
Amnesic Shellfish Poisoning

Abstract A liquid chromatography/mass spectrometry (LC/MS) method for amnesic shellfish poisoning toxins in shellfish was developed and validated. Tissue homogenate (4 g) was extracted with 16 mL methanol–water (1 + 1, v/v). Dilution into acetonitrile–water (1 + 9, v/v) was followed by C18 solid-phase extraction cleanup. Domoic acid (DA) and epi-domoic acid were determined by LC/MS/MS with electrospray ionization and multiple reaction monitoring. External calibration was performed with dilutions of a certified reference standard. Advantages of this method include speed, lower detection limits, and a very high degree of specificity. The LC/MS response was highly linear, and there were no significant interferences to the determination of DA. Formal method validation was performed on 4 shellfish species. Fortification studies gave recoveries (mean ± SD; n = 24) of 93 ± 14% at 1 mg/kg, and 93.3 ± 7.6% at 20 mg/kg over all the species. Analysis of a mussel certified reference material showed the bias as <5%. The limits of detection and quantitation were 0.15 and 0.5 mg/kg, respectively. Routine application of the method over 4 months gave a recovery for the QC sample (1 mg/kg fortified blank mussel homogenate) run with each batch of 88.9 ± 5.5% (mean ± SD; n = 37). The total uncertainty of measurement results were estimated as 0.12 (12%) at 0.25–5 mg/kg and 0.079 (7.9%) at 5–50 mg/kg. The major contribution to the uncertainty was the repeatability of the LC/MS determination, probably arising from subtle matrix effects.

scholarly journals Sensitive determination of domoic acid in mussel tissue using dansyl chloride derivatization and liquid chromatography-mass spectrometry

2015 ◽  
Vol 7 (3) ◽  
pp. 1000-1007 ◽  
Author(s):  
Daniel G. Beach ◽  
Hechun Liu ◽  
Michael A. Quilliam
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Domoic Acid ◽  
New Method ◽  
Liquid Chromatography Mass Spectrometry ◽  
Shellfish Poisoning ◽  
Mussel Tissue ◽  
Amnesic Shellfish Poisoning ◽  
Sensitive Determination

This paper describes a new method for sensitive determination of domoic acid (DA), the causative toxin of amnesic shellfish poisoning (ASP), in shellfish.

scholarly journals Development and Application of Immunoaffinity Column Purification and Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry for Determination of Domoic Acid in Shellfish

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 83 ◽  
Author(s):  
Si Chen ◽  
Xiaojun Zhang ◽  
Zhongyong Yan ◽  
Yangyang Hu ◽  
Yibo Lu
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Domoic Acid ◽  
Matrix Effects ◽  
Limit Of Detection ◽  
Multiple Reaction Monitoring ◽  
Ammonium Hydroxide ◽  
Tandem Mass ◽  
Immunoaffinity Column ◽  
Shellfish Poisoning

Domoic acid (DA) is a neurotoxin associated with amnesic shellfish poisoning (ASP). Though LC coupled to tandem mass spectrometry (LC-MS/MS) has become the preferred method for DA determination, traditional sample pretreatment is still labor-intensive. In this study, a simple, efficient and selective method for LC-MS/MS analysis of DA in shellfish was established by optimizing clean-up procedures on a self-assembly immunoaffinity column (IAC). Shellfish was extracted with 75% methanol twice and diluted with phosphate buffered saline (PBS, 1:2). The mixture was purified on IAC as follows: preconditioned with PBS, loaded with sample, washed by 50% MeOH, and eluted with MeOH containing 2% ammonium hydroxide. Concentrated analyte was monitored by multiple reaction monitoring (MRM) using electrospray (ESI) positive ion mode throughout the LC gradient elution. Based on the post-extraction addition method, matrix effects for various shellfish matrices were found to be less than 8%. The developed method was fully validated by choosing mussel as the representative matrix. The method had a limit of detection (LOD) of 0.02 µg·g−1, showed excellent linear correlation in the range of 0.05–40 µg·g−1, and obtained ideal recoveries (91–94%), intra-day RSDs (6–8%) and inter-day RSDs (3–6%). The method was successfully applied to DA determination in 59 shellfish samples, with a detection rate of 10% and contaminated content of 0.1–14.9 µg·g−1.

scholarly journals Tissue Distribution of Hirsutine and Hirsuteine in Mice by Ultrahigh-Performance Liquid Chromatography-Mass Spectrometry

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Quan Zhou ◽  
Jianshe Ma ◽  
Limei Chen
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Intraperitoneal Administration ◽  
Precipitation Method ◽  
Tissue Homogenate ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Ultrahigh Performance Liquid Chromatography

Hirsutine and hirsuteine were two alkaloid monomers extracted from the traditional Chinese medicine Uncaria rhynchophylla, which have pharmacological effects such as antihypertension, anti-infection, and heart protection. An ultrahigh-performance liquid chromatography-mass spectrometry was established for the determination of hirsutine and hirsuteine in tissues (liver, kidney, heart, spleen, brain, and lung), and their absorption, distribution, and metabolism were studied for providing information on its pharmacological mechanism. UPLC BEH C18 column (2.1  mm × 100  mm, 1.7 μm) was used for chromatographic separation. The mobile phase was acetonitrile-0.1% formic acid, with a gradient elution, and the total run time was 4 min. Electrospray was used in the positive ion mode, and the multiple reaction monitoring (MRM) mode was for quantification. The acetonitrile precipitation method was used to remove protein-treated mouse plasma and tissue homogenate samples. In the concentration range of 2–5000 ng/g, hirsutine and hirsuteine in tissues showed good linearity (r > 0.995), and the lower limit of quantification was 2 ng/g. In the plasma and liver tissues, the interday and intraday precision of hirsutine and hirsuteine was less than 15%, the accuracy was between 90.9% and 110.1%, and the average recovery was better than 73.0%. The matrix effect was between 86.2% and 104.7%. The results showed that the precision, accuracy, recovery, and matrix effects meet the requirements for the study on the distribution of hirsutine and hirsuteine. After intraperitoneal administration of 10 mg/kg hirsutine and hirsuteine in mice, the distribution levels were highest in liver and kidney tissues, followed by the spleen and lung. Hirsutine and hirsuteine were low in brain tissue, but had obvious distribution, suggesting that they may pass through the blood-brain barrier.

scholarly journals METHOD DEVELOPMENT AND VALIDATION OF LERCANIDIPINE IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY TANDEM-MASS SPECTROMETRY

2018 ◽  
Vol 10 (4) ◽  
pp. 87
Author(s):  
Yahdiana Harahap ◽  
Norma Andriyani ◽  
Harmita .
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Method Development ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Tandem Mass ◽  
Mass Detection ◽  
Column Temperature ◽  
Z Value

Objective: To obtain an optimum and validated method for analyzing lercanidipine in plasma using Ultra Performance Liquid Chromatography of Tandem Mass Spectrometry (UPLC-MS/MS).Methods: The separation was carried out using 1.7μm (2.1 x 100 mm) Waters AcquityTM UPLC C18 column, a mobile phase of the 0.1% formic acid-methanol mixture (20:80 v/v) with isocratic elution, 30 °C column temperature, 0.2 ml/min flow rate and amlodipine as an internal standard. Mass detection was performed with a positive XBL TQD type Electrospray Ionization (ESI) in Multiple Reaction Monitoring modes. Lercanidipine was detected at m/z value of 612.11>280.27 and amlodipine was detected at m/z value 409.1>238.15. The optimum sample preparation method was a liquid-liquid extraction using 5 ml of n-hexane-ethyl acetate (50:50 v/v), vortex mixed for 3 min, centrifuged at 4000 rpm for 20 min, evaporated with nitrogen at 50 °C for 30 min, and the residue was reconstituted with 100 μl of mobile phase.Results: The method was linear in the range of 0.025-10 ng/ml with r ≥ 0.9986. Accuracy and precision within-run and between-run met the requirements with %diff and %CV, not exceeding ± 15% and not more than ± 20% for Lower Limit of Quantification (LLOQ) concentration.Conclusion: It was concluded that the developed method met the requirements of selectivity, carry over, stability, the integrity of dilution, and matrix effects under the Guideline on Bioanalytical Method Validation by the European Medicines Agency in 2011. 

scholarly journals Ultraperformance Liquid Chromatography–Tandem Mass Spectrometry Assay for Iohexol in Human Serum

2009 ◽  
Vol 55 (6) ◽  
pp. 1196-1202 ◽  
Author(s):  
Thomas M Annesley ◽  
Larry T Clayton
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Human Serum ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Structural Analog ◽  
Limit Of Quantification ◽  
Iodinated Contrast ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Iohexol is an iodinated contrast dye that has been shown to be useful in the estimation of glomerular filtration rate (GFR) in patients with suspected renal insufficiency. We developed and validated an ultraperformance liquid chromatography (UPLC)–triple quadrupole mass spectrometry (MS/MS) assay for quantifying iohexol in human serum. Methods: Sample preparation involved dilution of 50 μL serum with 400 μL water, followed by protein precipitation with zinc sulfate and methanol containing the structural analog ioversol as the internal standard. After 1:20 dilution of the supernatant with water, 5 μL was injected into the UPLC-MS/MS system. Chromatography was performed using a Waters Oasis HLB 5-μm particle size, 2.1 × 20 mm column maintained at 50 °C. We used a 1-step acetonitrile/0.1% formic acid gradient to elute the compounds of interest at a common retention time of 0.96 min. The multiple reaction monitoring transitions used for integration and quantification were m/z 821.7→803.7 for iohexol and m/z 807.9→589.0 for ioversol in the electrospray positive ionization mode. Results: The assay was linear from 2.5 mg/L (lower limit of quantification) to 1500 mg/L iohexol, with a mean extraction efficiency of >99%. Recovery of nominal target concentrations was 99%–102%. Interassay imprecision ranged from 7.9% at a concentration of 2.5 mg/L to 4.1% at 1000 mg/L. Ion suppression studies showed no matrix effects on the ionization of the 2 compounds. Conclusions: This rapid UPLC-MS/MS method can be successfully used for quantifying iohexol in human serum. .

scholarly journals Determination and Confirmation of the Amnesic Shellfish Poisoning Toxin, Domoic Acid, in Shellfish from Scotland by Liquid Chromatography and Mass Spectrometry

2001 ◽  
Vol 84 (5) ◽  
pp. 1657-1667 ◽  
Author(s):  
Philipp Hess ◽  
Susan Gallacher ◽  
Lesley A Bates ◽  
Nigel Brown ◽  
Michael A Quilliam
Keyword(s):  
Liquid Chromatography ◽  
Domoic Acid ◽  
Pecten Maximus ◽  
Shellfish Poisoning ◽  
Mussel Tissue ◽  
Crude Extracts ◽  
Amnesic Shellfish Poisoning ◽  
Routine Monitoring ◽  
Strong Anion Exchange ◽  
Array Detection

Abstract During 1998 and early 1999, shellfish samples from sites in Scotland were found to contain the amnesic shellfish poisoning toxin, domoic acid (DA). Two different techniques, liquid chromatography (LC) with UV diode-array detection and LC with mass spectrometric (MS) detection, were used to detect and confirm DA in shellfish extracts. The LC/UV method was validated for routine monitoring by recovery experiments on spiked mussel and scallop tissues with a certified mussel tissue used as reference material. Crude extracts of selected samples as well as extracts cleaned with strong anion exchange (SAX) were analyzed by both LC/UV and LC/MS. Good correlation (linear regression r2 = 0.996, slope = 0.93) between the 2 methods was found for cleaned extracts. Analyses of crude extracts by LC/UV produced false-positive results in 2 crab samples, whereas LC/MS analyses gave accurate results. It was concluded that LC/UV is a valid approach for routine monitoring of DA in shellfish when cleanup is performed with a SAX cartridge to prevent false positives. A variety of shellfish species were surveyed for DA content, including Pecten maximus (king scallops), Chlamys opercularis (queen scallop), Mytilus edulis (blue mussels), Cancer pugaris (crab), and Ensis ensis (razor fish). The highest concentration of DA was 105 μg/g in Pecten maximus.

scholarly journals Sensitive Quantitative Analysis of C-Peptide in Human Plasma by 2-Dimensional Liquid Chromatography–Mass Spectrometry Isotope-Dilution Assay

2006 ◽  
Vol 52 (5) ◽  
pp. 872-879 ◽  
Author(s):  
Eduard Rogatsky ◽  
Beate Balent ◽  
Gayotri Goswami ◽  
Vlad Tomuta ◽  
Harsha Jayatillake ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Detection Limit ◽  
Isotope Dilution ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Plasma Concentrations ◽  
Liquid Chromatography Mass Spectrometry ◽  
C Peptide ◽  
Chromatography Mass Spectrometry

Abstract Background: Isotope-dilution assays (IDAs) are well established for quantification of metabolites or small drug molecules in biological fluids. Because of their increased specificity, IDAs are an alternative to immunoassays for measuring C-peptide. Methods: We evaluated a 2-dimensional liquid chromatography–mass spectrometry (2D LC/MS) IDA method. Sample preparation was by off-line solid-phase extraction, and C-peptide separation was performed on an Agilent 1100 2D LC system with a purification method based on high-pressure switching between 2 high-resolution reversed-phase columns. Because of the low fragmentation efficiency of C-peptide, multiple-reaction monitoring analysis was omitted and selective-ion monitoring mode was chosen for quantification. Native and isotope-labeled ([M+18] and [M+30]) C-peptides were monitored in the +3 state at m/z 1007.7, 1013.7, and 1017.7. Results: The assay was linear (r2 = 0.9995), with a detection limit of 300 amole (1 pg) on column. Inter- and intraday CVs for C-peptide were ≤2%. Comparison with an established polyclonal-based RIA showed high correlation (r = 0.964). Plasma concentrations of total C-peptide measured by RIA were consistently higher than by IDA LC/MS, consistent with the higher specificity of IDAs compared with immunoassays. Conclusions: The 2D LC/MS IDA approach eliminates matrix effects, enhancing assay performance and reliability, and has a detection limit 100-fold lower than any previously reported LC/MS method. Isotope-labeled C-peptide(s) can be clearly differentiated from endogenous C-peptide by the difference in m/z ratio, so that both peptides can be quantified simultaneously. The method is highly precise, robust, and applicable to pharmacokinetic detection of plasma peptides.

scholarly journals Determination of Pesticides in Soy-Based Infant Formula Using Liquid Chromatography with Electrospray Ionization Tandem Mass Spectrometry

2006 ◽  
Vol 89 (1) ◽  
pp. 214-224 ◽  
Author(s):  
Jian Wang ◽  
Wendy Cheung
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Infant Formula ◽  
Matrix Effects ◽  
Multiple Reaction Monitoring ◽  
Tandem Mass ◽  
Calibration Curves ◽  
Ionization Tandem Mass Spectrometry

Abstract A sensitive method using liquid chromatography with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) was developed and validated to quantify and confirm 13 pesticides, including aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, formetanate, 3-hydroxycarbofuran, carbendazim, thiabendazole, aldicarb, propoxur, carbofuran, carbaryl, and methiocarb, in soy-based infant formula. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of 2 fragment ion transitions to provide a high degree of sensitivity and selectivity for both quantitation and confirmation. Different approaches to constructing calibration curves were compared and discussed to address issues of the extraction efficiency or recovery, and matrix effects. Matrix-matched standard calibration curves with the use of isoprocarb as an internal standard were finally used to achieve the best accuracy of the method. Under most circumstances, recoveries of 13 pesticides, spiked at 5.0, 25.0, and 45.0 g/kg, were close to 100%. The method detection limits (signal-to-noise ratio 3:1; g/kg) of 13 pesticides were 0.2 for thiabendazole and methiocarb, 0.6 for aldicarb, and 0.1 for the others.

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