کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1199500 1493552 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A practical methodology to measure unbiased gas chromatographic retention factor vs. temperature relationships
ترجمه فارسی عنوان
یک روش عملی برای اندازه گیری رابطه غیرمستقیم گاز کروماتوگرافی گاز در برابر درجه حرارت
کلمات کلیدی
طرح ریزی نگهداری، پیش بینی احتباس، طیف سنجی جرم کروماتوگرافی گاز، کتابخانه نگهداری، پایگاه داده نگهداری
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
چکیده انگلیسی


• Retention factor vs. T relationships can be measured from six temperature programs.
• Measured this way, they are strongly biased by GC system non-idealities.
• The retention times of standards may be used to back-calculate the non-idealities.
• Once they are taken into account, the measured k vs. T relationships are unbiased.
• Software was developed to make the new methodology accessible and practical.

Compound identification continues to be a major challenge. Gas chromatography–mass spectrometry (GC–MS) is a primary tool used for this purpose, but the GC retention information it provides is underutilized because existing retention databases are experimentally restrictive and unreliable. A methodology called “retention projection” has the potential to overcome these limitations, but it requires the retention factor (k) vs. T relationship of a compound to calculate its retention time. Direct methods of measuring k vs. T relationships from a series of isothermal runs are tedious and time-consuming. Instead, a series of temperature programs can be used to quickly measure the k vs. T relationships, but they are generally not as accurate when measured this way because they are strongly biased by non-ideal behavior of the GC system in each of the runs. In this work, we overcome that problem by using the retention times of 25 n-alkanes to back-calculate the effective temperature profile and hold-up time vs. T profiles produced in each of the six temperature programs. When the profiles were measured this way and taken into account, the k vs. T relationships measured from each of two different GC–MS instruments were nearly as accurate as the ones measured isothermally, showing less than two-fold more error. Furthermore, temperature-programmed retention times calculated in five other laboratories from the new k vs. T relationships had the same distribution of error as when they were calculated from k vs. T relationships measured isothermally. Free software was developed to make the methodology easy to use. The new methodology potentially provides a relatively fast and easy way to measure unbiased k vs. T relationships.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1374, 29 December 2014, Pages 207–215
نویسندگان
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