Assignment:
Question 1. 2g sample of harbour sediment was digested in aqua regia and then the filtered solution made up to 50mL and analysed by flame atomic absorption, giving a concentration of 4.6mg/L of Zinc. What was the concentration of Zinc, in mg/Kg in the sediment?
Question 2. 100µL sample of petrol for analysis was diluted to 10mL with pentane containing naphthalene as internal standard. A standard was also prepared in the same way, containing 10µL of toluene in 10mL of pentane, also with naphthalene at the same concentration. Portions (1µL) of each were injected and the following peak areas were recorded:
Standard Toluene 2345 Naphthalene 3470
Sample Toluene 3170 Naphthalene 3250
What was the concentration of Toluene in the petrol expressed as % v/v?
Provide complete and step by step solution for the question and show calculations and use formulas.