کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7610978 1493502 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
High temperature diaphragm valve-based comprehensive two-dimensional gas chromatography
ترجمه فارسی عنوان
کروماتوگرافی گاز دو بعدی جامد بر روی دیافراگم درجه حرارت بالا
کلمات کلیدی
کروماتوگرافی گازی، جامع دو بعدی، مبتنی بر شیر درجه حرارت بالا،
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
چکیده انگلیسی
A high-temperature diaphragm valve-based comprehensive two-dimensional gas chromatography (GC × GC) instrument is demonstrated which readily allows separations up to 325 °C. Previously, diaphragm valve-based GC × GC was limited to 175 °C if the valve was mounted in the oven, or limited to 265 °C if the valve was faced mounted on the outside of the oven. A new diaphragm valve has been commercially developed, in which the temperature sensitive O-rings that previously limited the separation temperatures have been replaced with Kalrez O-rings, a perfluoroelastomer, allowing for significantly higher temperatures permitting a greater range of volatile and semi-volatile compounds to be readily separated. In the current investigation, a separation temperature up to 325 °C is demonstrated with the valve mounted directly in the oven. Since the temperature limit for most commonly used GC columns is at or below 325 °C, the scope of diaphragm valve-based GC × GC is now dramatically broadened to encompass a majority of all column stationary phase chemistries. A 44-component mixture of alkanes, alcohols, and polyaromatic hydrocarbons is used to study this new configuration whose boiling points range from 98 °C (n-heptane) to 450 °C (n-triacontane). For the test mixture using a modulation period PM of 1.0 s, peak shapes on second dimension separations, 2D, are symmetric with average widths at base of 79.4 ms, producing a 2D peak capacity of 2nc ∼ 12. Based on the average peak width of 2.4 s for the first dimension separation with a run time of 32.5 min, the 1D peak capacity is 1nc ∼ 800. Thus, the ideal two-dimensional peak capacity nc,2D is 9600. Little variation in within-analyte 2D peak width was observed with an average %RSD of less than 3.0%. Furthermore, retention time on 2D was very reproducible with an average %RSD less than 0.5%. Measured peak areas (sum of all 2D peaks for given analyte) had an average %RSD of 4.4%. The transfer fraction from 1D to 2D was experimentally determined to be ∼30%, while the detection sensitivity for valve-based GC × GC was ∼8 times higher than one dimensional GC due to zone compression. After a year of use with temperatures consistently up to 325 °C, there has been no deterioration of the valve or its performance for GC × GC. Separations of vacuum pump oil and orange oil are also reported to demonstrate practical utility.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1424, 11 December 2015, Pages 127-133
نویسندگان
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