The QMSup>庐up> technique is based on a competitive inhibition of turbidity in presence of free lamotrigine. On the CDx90up>庐up>, calibration is carried out in six points from 0 to 40 mg/L with detection at 700 nm (end point or kinetic). Serum samples from 17 epileptic patients were compared with an HPLC technique. Statistics were performed with Methvalup>庐up> software (P < 0.05).
With the kinetic mode, limit of quantification is 0.70 mg/L. Between run, precision (n = 15) is 4.4%(2 mg/L), 4.0%(15 mg/L) and 6.4%(25 mg/L). There is no correlation with time up to 15 mg/L (rup>2up> = 0.060) and bias is less than 鈭?.1%for at least 16 weeks. Patient results (0.83 to 13.88 mg/L) correlate with HPLC (rup>2up> = 0.984聽; P < 0.05) with a mean negative bias of 鈭?.9 mg/L (or 鈭?.1%) (P < 0.05).
The QMSup>庐up> lamotrigine reagent on CDx90up>庐up> permits a fast (15 min) and easy determination of this molecule in serum within the therapeutic range in epilepsy (2.5-15 mg/L).