} \\ {\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \  + \text{free}\ \text{cotinine}\ \left\lbrack \mu\text{mol/L} \right\rbrack + \text{cotinine} - \text{glucuronide}\ \left\lbrack \mu\text{mol/L} \right\rbrack} \\ {\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \  + \text{free}\ \text{trans} - \text{0}' - \text{hydroxycotinine}\ \left\lbrack \mu\text{mol/L} \right\rbrack} \\ {\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \  + \text{trans} - \text{0}' - \text{hydroxycotinine} - \text{glucuronide}\ \left\lbrack \mu\text{mol/L} \right\rbrack