Various authors [5–7] have determined HQ by various techniques such as high performance liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC–MS) and voltammetry [8,9] in different types of samples. Colorimetric analysis of small amount of HQ in styrene has also been reported [10]. Spectrophotometric determination of HQ has also been cited elsewhere [11–14]. All the workers employing these techniques have tried to modify sensitivity of the method after optimization of the relative parameters.