Abstract ▼ AI-Helper

In this study, a new headspace wire coated in-needle microextraction (HS-WC-INME) methodology combined with gas chromatography (GC) is developed and evaluated. To our knowledge, this is the first report on the use of nichrome wire coated with a mixture of poly(ethylene glycol) (PEG) and poly(dimethy...

In this study, a new headspace wire coated in-needle microextraction (HS-WC-INME) methodology combined with gas chromatography (GC) is developed and evaluated. To our knowledge, this is the first report on the use of nichrome wire coated with a mixture of poly(ethylene glycol) (PEG) and poly(dimethylsiloxane) (PDMS) in HS-INME. A nichrome wire (200 μm O.D., 39 mm length) coated with 50% aqueous PEG and PDMS mixture (1:1 wt/wt ratio, ca. 35μm thickness, 10 mm length) was inserted to a stainless steel needle inside (21gauge, 819μm O.D., 514 μm I.D., 39 mm length). The prepared needle for microextraction was hooked simply to a luer lock gas tight syringe barrel (Hamilton 1001N, 1 mL)and a plunger made of Teflon, then inserted and exposed into the headspace (HS) over the sample. HS sampling prior to GC or GC-MS separation was speeded up by pulling-up and pushing-down of the Teflon plunger in the glass barrel using an automatic reciprocating piston. The extracted analytes were transferred to the GC column through thermal desorption at the heated GC injector. The HS-WC-INME conditions were optimized for 30 min extraction at 50oC and 2 min desorption at 240oC to 10 polar and non-polar analytes. Excellent linearity was observed over the entire working concentration ranges with determination coefficient (r2) greater than 0.99. Its results showed low detection limits, good recovery, and reproducibility. The method was applied successfully to analyze yuza (Korean citron) oil, lavender oil, rose perfume and maehwa (Asian plum) blossoms. This solvent-free and durable device is inexpensive to fabricate, simple to operate, reusable, fast and efficient for sampling of both polar and non-polar aroma compounds in essential oils or botanical samples. The proposed method could be more suitable to extract particular polar groups such as alcohols. The research results proved that the present method is a newly and efficiently developed one which may complement the drawback of current headspace sampling methods.

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