scholarly journals Radiocarbon Dating of Single Compounds Isolated from Pottery Cooking Vessel Residues

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 191-197 ◽  
Author(s):  
A W Stott ◽  
R Berstan ◽  
P Evershed ◽  
R E M Hedges ◽  
C Bronk Ramsey ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Stearic Acid ◽  
Systematic Error ◽  
Radiocarbon Dating ◽  
Measurement Process ◽  
Lipid Material

We have developed and demonstrated a practical methodology for dating specific compounds (and octade-canoic or stearic acid—C18:0—in particular) from the lipid material surviving in archaeological cooking pots. Such compounds may be extracted from about 10 g of cooking potsherd, and, after derivatization, can be purified by gas chromatography. To obtain sufficient material for precise dating repetitive, accumulating, GC separation is necessary. Throughout the 6000-year period studied, and over a variety of site environments within England, dates on C18:0 show no apparent systematic error, but do have a greater variability than can be explained by the errors due to the separation chemistry and measurement process alone. This variability is as yet unexplained. Dates on C16:0 show greater variability and a systematic error of approximately 100-150 years too young, and it is possible that this is due to contamination from the burial environment. Further work should clarify this.

scholarly journals Fatty acid chemistry of Atrichum undulatum and Hypnum andoi

2012 ◽  
Vol 66 (2) ◽  
pp. 207-209 ◽  
Author(s):  
Boris Pejin ◽  
Ljubodrag Vujisic ◽  
Marko Sabovljevic ◽  
Vele Tesevic ◽  
Vlatka Vajs
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Linolenic Acid ◽  
Essential Fatty Acids ◽  
Behenic Acid ◽  
Moss Species

The fatty acid composition of the moss species Atrichum undulatum (Hedw.) P. Beauv. (Polytrichaceae) and Hypnum andoi A.J.E. Sm. (Hypnaceae) collected in winter time were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) as a contribution to their chemistry. Eight fatty acids were identified in the chloroform/methanol extract 1:1 of A. undulatum (linoleic acid 26.80%, palmitic acid 22.17%, ?-linolenic acid 20.50%, oleic acid 18.49%, arachidonic acid 6.21%, stearic acid 3.34%, cis-5,8,11,14,17-eicosapentaenoic acid 1.52% and behenic acid 1.01%), while six fatty acids were found in the same type of extract of H. andoi (palmitic acid 63.48%, erucic acid 12.38%, stearic acid 8.08%, behenic acid 6.26%, lignoceric acid 5.16% and arachidic acid 4.64%). According to this study, the moss A. undulatum can be considered as a good source of both essential fatty acids for humans (linoleic acid and ?-linolenic acid) during the winter.

scholarly journals Determination ofMagnesium Stearate in Capsule- or Tablet-Type Supplements

2006 ◽  
Vol 89 (2) ◽  
pp. 458-461 ◽  
Author(s):  
Yoko Uematsu ◽  
Mami Ogimoto ◽  
Junichirou Kabashima ◽  
Kouichi Ito ◽  
Kazuo Yasuda
Keyword(s):  
Gas Chromatography ◽  
Stearic Acid ◽  
Cation Exchange ◽  
Acid Concentration ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Magnesium Stearate ◽  
Positive Error ◽  
Simple Method

Abstract A simple method for the determination of magnesium stearate in capsule- or tablet-type supplements was developed. Free stearic acid in the sample was removed by extraction with tetrahydrofuran. The remaining stearate was converted to stearic acid by reaction with a cation-exchange resin. The resulting stearic acid was determined by gas chromatography with a polar column. Esters of stearic acid were not converted to stearic acid and would not cause a positive error in the amount of stearate. The amount of magnesium stearate was calculated based on the stearic acid concentration thus obtained. Magnesium stearate levels in 5 out of 25 supplements exceeded 2500 g/g, which indicated the possible admixture of magnesium stearate.

Collaborative Study of the Gas Chromatographic Determination of Six Thiocarbamate Herbicides in Formulations

1974 ◽  
Vol 57 (1) ◽  
pp. 53-59
Author(s):  
James E Barney
Keyword(s):  
Gas Chromatography ◽  
Systematic Error ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization Detector ◽  
Ionization Detector ◽  
Flame Ionization

Abstract Eptam, Ordram, Ro-Neet, Sutan, Tillam, and Vernam thiocarbamate herbicides are determined in emulsifiable and granular formulations by gas chromatography on an OV-1, SE-30, or OV-17 column with a flame ionization detector. Another thiocarbamate is used as an internal standard. The method was tested collaboratively by 19 laboratories, 18 of which tested the method on all 6 thiocarbamates. The coefficient of variation for 12 formulations was 3.10%. A significant amount of systematic error was detected, particularly in the analysis of emulsifiable formulations. The method has been adopted as official first action, and it is recommended that additional studies be conducted.

Collaborative Study of the GLC Determination of Glycerine and Propylene Glycol in Tobacco

1969 ◽  
Vol 52 (4) ◽  
pp. 753-756
Author(s):  
J A Giles ◽  
R H Cundiff
Keyword(s):  
Gas Chromatography ◽  
Systematic Error ◽  
Propylene Glycol ◽  
Standard Method ◽  
Collaborative Study ◽  
Standard Deviations

Abstract A method for the methanolic extraction of glycerine and propylene glycol from tobacco and their determination by gas chromatography was collaboratively studied by 11 laboratories. Results show unacceptably high systematic error standard deviations. Additional study and refinement of the procedure will be required before it is suitable as a standard method.

scholarly journals Methyl Esterification Combined with Gas Chromatography-Mass Spectrometry (GC-MS) for Determining the Contents of Lubricant to Evaluate the Compatibility of Chlorinated Butyl Rubber Stoppers with Liposome Injections

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xun Gao ◽  
Kexin Chen ◽  
Miaomiao Chi ◽  
Kunming Qin
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Methyl Stearate ◽  
Butyl Rubber ◽  
Gas Chromatography Mass Spectrometry ◽  
Methyl Esterification ◽  
Chromatography Mass Spectrometry ◽  
Chlorinated Butyl Rubber

A simple, sensitive, and exact methyl esterification in combination with gas chromatography-mass spectrometry (GC-MS) method was developed to determine the contents of palmitic acid and stearic acid in the chlorinated butyl rubber stoppers and liposome injections in order to evaluate the compatibility of pharmaceutical packaging materials. In this experiment, palmitic acid and stearic acid were detected in the form of methyl hexadecanoate and methyl stearate in chlorinated butyl rubber stoppers and liposome injections. The results showed good linearities in the range of 0.50–10.00 µg·mL−1 for methyl hexadecanoate and 1.00–20.00 µg·mL−1 for methyl stearate, with the limits of detection (LOD) 11.94 ng·mL−1 and 11.90 ng·mL−1, respectively. The recoveries that ranged from 95.25% to 100.29% were satisfied, and the relative standard deviation (RSD) was no more than 7.16%. The developed method was successfully applied to evaluate the compatibility of chlorinated butyl rubber stoppers with liposome injections and the safety assessment.

Analysis of Radiolytic Products of Lipid in Irradiated Dried Squids (Todarodes pacificus)

2004 ◽  
Vol 67 (8) ◽  
pp. 1731-1735 ◽  
Author(s):  
JUN-HYOUNG KIM ◽  
HYE-YOUNG SEO ◽  
KYONG-SU KIM
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
International Trade ◽  
Food Safety ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Radiation Dosage ◽  
Florisil Column ◽  
Todarodes Pacificus ◽  
Radiation Induced

The lipid portion of dried squids (Todarodes pacificus) was extracted, and its hydrocarbons and 2-alkylcyclobutanones were separated using a florisil column. Both compounds were identified by gas chromatography and mass spectrometry and used to investigate the production of radiation-induced hydrocarbons and 2-alkylcyclobutanones. Concentrations of the hydro-carbons and 2-alkylcyclobutanones increased linearly with the radiation dosage. The major hydrocarbons in the irradiated dried squids were pentadecane and 1-tetradecene, which originated from palmitic acid. The amount of pentadecane was the highest among the radiation-induced hydrocarbons in the dried squids. The major 2-alkylcyclobutanone in the irradiated dried squids was 2-dodecylcyclobutanone, which was formed from the large amount of palmitic acid. 2-Tetradecylcyclobutanone, which may be produced from stearic acid in sample lipids, was also detected. Radiation-induced hydrocarbons and 2-alkylcyclobutanones were detected at ≥0.5 kGy. These compounds were not detected in dried squids that were not irradiated. Radiation-induced hydrocarbons can be used as a detection marker for irradiated dried squids; however, the amount of 2-alkylcyclobutanones produced was not enough to be used as a marker. Radiolytic products of lipids, such as hydrocarbons or 2-alkylcyclobutanones, can be used to monitor food safety for consumers, ensuring proper irradiation labeling in foods and quarantine treatment in international trade.

Sign in / Sign up

Export Citation Format

Share Document