scholarly journals Precision and accuracy in the determination of organics in water by fused silica capillary column gas chromatography/mass spectrometry and packed column gas chromatography/mass spectrometry

1983 ◽  
Vol 55 (9) ◽  
pp. 1471-1479 ◽  
Author(s):  
James W. Eichelberger ◽  
Edward H. Kerns ◽  
Paul. Olynyk ◽  
William L. Budde
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Packed Column ◽  
Fused Silica ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Fused Silica Capillary ◽  
Capillary Column Gas Chromatography ◽  
Silica Capillary Column

Postmortem Analysis of Benzodiazepines in Human Bone by Gas Chromatography–Mass Spectrometry

2020 ◽  
Author(s):  
Rosanna Mancini ◽  
Lucia Fernadez-Lopez ◽  
Maria Falcon ◽  
Manuela Pellegrini ◽  
Aurelio Luna ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Internal Standard ◽  
Fused Silica ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Fused Silica Capillary ◽  
Silica Capillary Column

Abstract A procedure based on gas chromatography-mass spectrometry was developed for the analysis of benzodiazepines (nordiazepam, oxazepam, lormetazepam, lorazepam, clonazepam, bromazepam and alprazolam) in postmortem human ribs. Powdered bone samples, including marrow remains inside, with the internal standard diazepam-d5 were subjected to enzymatic hydrolysis with 100 μL of β-glucoronidase and were incubated in sodium hydroxide for 1 h in a 70°C oven. Samples underwent liquid phase extraction and ethyl acetate was used as eluent. Chromatography was performed on a fused silica capillary column and the selected-ion-monitoring mode was used for analytes determination. The method was validated in the range 0.1–0.5 ng/mg (depending on the benzodiazepine) to 100 ng/mg with average values of recovery, matrix effect and process efficiency ranged from 83.2 to 94.3%, from 97.3 to 102.1% and from 80.5 to 91.2%, respectively. The intra- and inter-day accuracy was <15%. The procedure was tested in rib specimens obtained during routine autopsies from 20 cases where these benzodiazepines were found in blood. Benzodiazepines were detected in the combined bone and marrow samples in 60% of cases. Lorazepam was detected in bone in the range of 0.3–0.7 ng/mg, nordiazepam at 1.3–4.2 ng/mg and oxazepam at 1.1–1.2 ng/mg. To our knowledge, this protocol for the simultaneous analysis of these benzodiazepines is the first performed and validated using human ribs.

Determination of Phytosterols in Butter Samples by Using Capillary Column Gas Chromatography

1987 ◽  
Vol 70 (5) ◽  
pp. 912-915 ◽  
Author(s):  
Randall L Smith ◽  
Darryl M Sullivan ◽  
Earl F Richter
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Retention Time ◽  
Capillary Column ◽  
Limit Of Detection ◽  
Packed Column ◽  
Gas Chromatography Mass Spectrometry ◽  
Positive Bias ◽  
Capillary Column Gas Chromatography

Abstract A positive bias in the gas chromatographic (GC) analysis of butter for β-sitosterol was discovered when attempting to confirm values by gas chromatography/mass spectrometry (GC/MS). The source of the problem was traced to an interfering material that was not effectively separated by packed column GC. Because capillary columns are known to provide superior separation, they were substituted for packed columns in the assay, and instrument parameters were modified accordingly. A compound with a similar retention time, identified by GC/MS as lanosterol, was separated from β-sitosterol by the capillary column. The capillary column technique was applied to over 300 butter samples. The results indicate that the method can accurately quantitate β-sitosterol in butter with no known interferences. The limit of detection for this method is 1 mg/100 g. Recoveries at a level of 3 mg/100 g averaged 98% with a coefficient of variation of 3.45%

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