Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Original Papers
Ethyl Chloroformate as a Derivatizing Reagent for the Gas Chromatographic Determination of Isoniazid and Hydrazine in Pharmaceutical Preparations
Mohammad Yar KHUHAWARLiaquat Ali ZARDARI
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2008 Volume 24 Issue 11 Pages 1493-1496


Ethyl chloroformate was examined as a precolumn derivatizing reagent for the gas chromatographic (GC) determination of isoniazid (INH) and hydrazine (HZ). Phenylhydrazine (PHZ) was used as an internal standard. GC separation was carried out on an HP-5 column (30 m × 0.32 mm i.d.) with flame ionization detection. The elution was carried out at an initial column temperature of 150°C for 1 min at a heating rate of 10°C/min up to 250°C, nitrogen flow rate of 4 ml/min and a split ratio of 10:1, v/v. The linear calibration ranges for INH and HZ were observed between 3.5 - 37.5 and 3.5 - 35 µg/ml with corresponding detection limits of 0.18 and 0.17 ng reaching the detector. The method was subsequently applied to the determination of INH and HZ in pharmaceutical preparations, achieving a relative standard deviation (RSD) of 3.8 - 5.8%. The recovery percentage of INH from isoniazid syrup was 98% with an RSD of 5.2%.

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© 2008 by The Japan Society for Analytical Chemistry
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