16,429 research outputs found
Development and Validation of a HS-SPME-GC-SIM-MS Multi-Method Targeting Hop-Derived Esters in Beer
No full textHop-derived esters contribute to beer flavor and changes in the ester spectrum are believed to be an important driver in the flavor–instability of hoppy beers. To date, there exists no published method that enables reliable quantification of hop-derived esters in beer. As the availability of such a method is vital to enlarge the understanding of beer flavor stability, the current article is concerned with the development, validation, and application of a headspace solid phase microextraction gas chromatography selected ion monitoring mass spectrometry (HS-SPME-GC-SIM-MS) based methodology for quantification of 16 hop-derived esters in beer. The validation data shows that choosing suitable HS-SPME-GC-SIM-MS conditions enabled reliable quantification of esters across a range of 1–200 µg/L, with calculated limits of quantification being well below 1 µg/L. Spiking experiments using terpenes and terpenoids evidenced method robustness, most importantly when two commercially available stable isotope labeled internal standards (d6-geranyl acetate and 13C-methyl octanoate) were used. Application to beer samples indicated that beers brewed with different qualities/quantities of hops and differing in freshness could be well differentiated by HS-SPME-GC-SIM-MS analysis of their ester profile. Supplemental data for this article is available online at at https://doi.org/10.1080/03610470.2021.1994814 .</p
Ms. Courtney Chartier, RWWL AUC, August 2011
No full textThis video is a conversation with Ms. Courtney Chartier. Ms. Chartier talks about her work on the "New Georgia Encyclopedia" and "Online Voter Education Project." Andrea Jackson, AUC Woodruff Library, is the interviewer
Multiresidue Pesticide Analysis in Fresh Produce by Capillary Gas Chromatography−Mass Spectrometry/Selective Ion Monitoring (GC-MS/SIM) and −Tandem Mass Spectrometry (GC-MS/MS)
No full textA multiresidue method for the analysis of pesticides in fresh produce has been developed using salt-out acetonitrile extraction, solid-phase dispersive cleanup with octadecyl-bonded silica (C18), and graphitized carbon black/primary−secondary amine (GCB/PSA) sorbents and toluene, followed by capillary gas chromatography−mass spectrometry in selected ion monitoring mode (GC-MS/SIM) or −tandem mass spectrometry (GC-MS/MS). Quantitation was determined from calibration curves using matrix-matched standards ranging from 3.3 to 6667 ng/mL with r2 > 0.99, and geometric mean limits of quantitation were typically 8.4 and 3.4 μg/kg for GC-MS/SIM and GC-MS/MS, respectively. Identification was determined by using target and qualifier ions and qualifier-to-target ratios for GC-MS/SIM and two ion transitions for GC-MS/MS. Fortification studies (10, 25, 100, and 500 μg/kg) were performed on 167 organohalogen, organophosphorus, and pyrethroid pesticides in 10 different commodities (apple, broccoli, carrot, onion, orange, pea, peach, potato, spinach, and tomato). The mean percent recoveries were 90 ± 14, 87 ± 14, 89 ± 14, and 92 ± 14% for GC-MS/SIM and 95 ± 22, 93 ± 14, 93 ± 13, and 97 ± 13% for GC-MS/MS at 10, 25, 100, and 500 μg/kg, respectively. GC-MS/MS was shown to be more effective than GC-MS/SIM due to its specificity and sensitivity in detecting pesticides in fresh produce samples. The method, based on concepts from the multiresidue procedure used by the Canadian Food Inspection Agency and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe), was shown to be efficient in screening, identifying, and quantitating pesticides in fresh produce samples
Ms. Neely Terrell, RWWL AUC, March 2012
No full textThis video is a conversation with Ms. Neely Terrell. Ms. Terrell talks about her book, "Super Singles Activate". Anthony Kinsey and Jahnesta Horney, AUC Woodruff Library, are the interviewers
The Goat Castle Murder: A True Natchez Story that Shocked the World / Sim C. Callon and Carolyn Vance Smith
No full textSim C. Callon and Carolyn Vance Smith. The Goat Castle Murder: A True Natchez Story that Shocked the World. Natchez, MS: Plantation Publishing Company, 1986.https://egrove.olemiss.edu/ms_mystery/1187/thumbnail.jp
<i>Sarracenia</i> accessions for targeted coniine analysis by GC-MS (SIM).
No full textSarracenia accessions for targeted coniine analysis by GC-MS (SIM).</p
Ms. Felesha Love, Spelman College, January 2016
No full textThis video is a conversation with Felesha Love. Ms. Love talks about her book, "Brave Leap to Freedom: Integrating Mind, Body, and Spirit to Cultivate Healthy Relationships". Jordan Moore, AUC Woodruff Library, is the interviewer
Validation parameters of GC-MS (SIM) analysis of 29 reference substances.
No full text<p>Validation parameters of GC-MS (SIM) analysis of 29 reference substances.</p
Additional file 1 of SIMAT: GC-SIM-MS data analysis tool
No full textParameter settings and compound names including derivatization. This file includes parameter settings used in MetaboliteDetector and AMDIS. It also includes the name of the compounds in Table 3 with the derivatization as listed in NIST GC-MS library. (PDF 190 kb
Validated LC–MS/MS method for simultaneous determination of SIM and its acid form in human plasma and cell lysate: Pharmacokinetic application
No full textAbstractSimvastatin (SIM) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor widely used in hyperlipidemia therapy. SIM has recently been studied for its anticancer activity at doses higher than those used for the hyperlipidemia therapy. This prompted us to study the pharmacokinetics of high-dose SIM in cancer patients. For this purpose, an LC–MS/MS method was developed to measure SIM and its acid form (SIMA) in plasma and peripheral blood mononuclear cells (PBMCs) obtained from patients. Chromatographic analyte separation was carried out on a reverse-phase column using 75:25 (% v/v) acetonitrile:ammonium acetate (0.1M, pH 5.0) mobile phase. Detection was performed on a triple quadrupole mass spectrometer, equipped with a turbo ion spray source and operated in positive ionization mode. The assay was linear over a range 2.5–500ng/mL for SIM and 5–500ng/mL for SIMA in plasma and 2.5–250ng/mL for SIM and 5–250ng/mL for SIMA in cell lysate. Recovery was >58% for SIM and >75% for SIMA in both plasma and cell lysate. SIM and SIMA were stable in plasma, cell lysate and the reconstitution solution. This method was successfully applied for the determination of SIM and SIMA in plasma and PBMCs samples collected in the pharmacokinetic study of high-dose SIM in cancer patients
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