(a) A student has prepared a mixture of benzoic acid (pKo: 4.20) and aniline (pkb: 9.40) in a buffer solution of pH 2.0. The mixture was extracted using 15 mL of diethyl ether. Analyse the extraction efficiency. (7 marks) NH, Benzoic acid Aniline Explain the procedure of QUECHERS method that can be used for the extraction of pesticide residues in fruit sample. (8 marks) (b) (c) There are two modes of hollow fiber liquid phase microextraction (HF-LPME). Justify the suitable mode of HF-LPME for the determination of salicylic acid (pKo: 3.00) in a urine sample. (10 marks) of