The Determination of Six Ionophore Coccidiostats in Feed by Liquid Chromatography with Postcolumn Derivatisation and Spectrofotometric/Fluorescence Detection

Table 3

The results of in house validation: recovery and precision of the determination of six ionophore coccidiostats in feed samples.

Coccidiostat	Target concentration, mg/kg	Mean concentration, mg/kg	Recovery, %	RSDr, %	RSDR, %	Horrat*
LAS	5.0; 25; 50; 100; CFS	5.42; 24.3; 44.4; 85.8; 60.9	109; 97; 89; 86; —	6.5; 2.0; 0.4; 1.7; 1.7	—; 4.0; 2.8; 3.4; 5.9	0.50; 0.40; 0.32; 0.43; 0.68
MAD	1.0; 5.0; 10; 20	1.10; 4.83; 10.5; 19.2	110; 97; 105; 96	5.2; 2.5; 1.7; 1.6	—; 5.1; 5.4; 3.4	0.33; 0.41; 0.47; 0.33
MON	5.0; 25; 50; 100	5.00; 23.2; 49.7; 94.3	100; 93; 99; 94	2.8; 2.0; 1.3; 1.0	—; 4.4; 5.3; 2.7	0.18; 0.44; 0.59; 0.34
NAR	5.0; 25; 50; 100; CFS	4.60; 23.3; 47.7; 91.2; 47.2	92; 93; 95; 91; —	5.4; 2.4; 0.4; 4.0; 3.8	—; 4.6; 1.3; 4.1; 6.5	0.42; 0.47; 0.14; 0.51; 0.73
SAL	5.0; 25; 50; 100; CFS	4.52; 23.9; 50.5; 91.1; 63.3	90; 95; 101; 91; —	3.2; 2.3; 1.5; 4.8; 3.6	—; 4.3; 5.2; 5.1; 5.2	0.25; 0.44; 0.58; 0.64; 0.61
SMD	5.0; 25; 50; 100	4.65; 21.3; 48.5; 89.6	93; 85; 97; 90	6.6; 1.3; 2.0; 1.1	—; 5.8; 3.6; 3.2	0.51; 0.58; 0.40; 0.40

RSD_r: relative standard deviation of repeatability, RSD_R: relative standard deviation of in house reproducibility.
CFS: commercial target feed sample.
∗Horrat ratio is calculated from repeatability for the lowest spiking level and from in house reproducibility for all other samples.