Table 4.

Recovery (%) and matrix effect (%) data for LNG (n=6)

		%Recovery (RE)	%Matrix Effect (ME)	%Process Efficiency (PE)	%Analysis RE
LQC	Mean	88.94	97.85	87.04	93.62
(134 pg/mL)	% CV	8.33	3.25	4.22	3.54
MQC	Mean	89.95	92.39	83.10	87.04
(420 pg/mL)	% CV	3.29	3.23	5.64	6.87
HQC	Mean	80.93	97.70	79.07	94.78
(1200 pg/mL)	% CV	6.10	0.49	3.18	2.14
Overall	Mean	85.03	98.78	83.07	91.81
	% CV	4.71	1.75	4.80	4.55
LNG-d7 (IS)	Mean	83.94	92.35	82.98	–
	% CV	3.29	3.23	4.36	–

Abbreviations: LNG, levonorgestrel; LQC, low quality control; MQC, medium quality control; HQC, high quality control.