Figure 1: Chromatogram for standard solution ortho-cresol of concentration 5 μg/ml (a), extracted blank urine (b) and extracted blank urine spiked with final concentration of 1 μg/ml of ortho-cresol (c) at optimized conditions, retention time 3.7 min. Note: Figure 1 (b) blank urine peak area is 6835 and for (c) urine spiked with 1 μg/ml of o-cresol peak area is 9678