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[交流] HCH异构体GCMS测定

在一篇文献上看到的，但不知道具体步骤和操作。说的很简单，氯仿提取，氮吹至20mL。还要用到phenanthrene-d10,不知道为什么。步骤我粘贴下，希望有大神能解惑。

The freeze-dried samples were extracted in chloroform during 45 min at 60 °C. The volume was reduced to 20 mL under nitrogen flow.
HCH isomers in organic extracts were quantified using GC-2010 plus (Shimadzu) gas chromatograph equipped with a DB 5-MS column (60 m × 0.25 mm i.d. × 0.1μm film thickness) coupled to a QP2012 Ultra (Shimadzu) mass spectrometer operated in full scan mode for each fraction. The oven temperature in GC was programmed from 70 °C (held 2 min) to 130 °C at 15 °C min-1, then from 130 °C to 315 °C (held 2 min) at 4 °C min-1. For HCH quantification, phenanthrene-d10, added in the organic extract before the GC-MS analysis, was used as internal standard (retention time close to HCH isomer in our analytical condition) and a solution of pesticide mix (including α-, γ-, β- and δ-HCH) was used for the GS-MS calibration (CLP Organochlorine Pesticide Mix, Supelco). Calibration curves were drawn for each quantified compound (α-, γ-, β- and δ-HCH) after the injection of six calibration solutions from the pesticide mix at 0.75, 1.5, 3, 4.5, 6 and 9 μg/mL and the phenanthrene-d10 as internal standards at 4 μg. mL-1. These curves were linear in the studied range and the determination coefficients were superior to 0.99. The overall calibration was verified with a calibration check standard analysis every 12 samples and a deviation lower than 20% is accepted. The average limit of quantification (LOQ) for the GC-MS is of 0.75 mg.kg-1 for each individual HCH without dilution step. Experimental and analytical blanks are also monitored regularly to assess external contamination.

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