Determination of Glyphosate, Glufosinate, and Their Major Metabolites in Tea Infusions by Dual-Channel Capillary Electrophoresis following Solid-Phase Extraction

Table 1

Salient performance data for the determinations of GLYP, GLUF, AMPA, and MPPA with the purpose-made CE-C4D system. Conditions: channel 1: GLYP, GLUF, and MPPA analysis: BGE solution: 1.0 M His/Ace (pH = 3.0); voltage: 20 kV; capillary: uncoated fused silica, 50 µm ID, L_t = 70 cm (L_eff = 49 cm). Channel 2: AMPA analysis: BGE solution: 30 mM His/MOPS (pH = 6.7); voltage: 20 kV; capillary: uncoated fused silica, 50 µm ID, L_t = 70 cm (L_eff = 62 cm).

Analytes	MDL (µg/L)	MQL (µg/L)	Linear range (µg/L)	Linearity (R^2)	Intra-assay precision (n = 7)		Interassay precision (10 days)		Recovery (%)
					RSD % for PA	RSD % for MT	RSD % for PA	RSD % for MT
GLYP	0.80	2.68	5.0–100	0,999	6.2	0.8	8.3	6.1	87.5–99.6
MPPA	0.56	1.87	5.0–100	0,998	4.6	0.7	8.9	5.8	83.5–88.4
GLUF	1.56	5.19	5.0–100	0,998	5.6	0.6	8.3	5.5	88.7–92.8
AMPA	0.54	1.82	5.0–100	0,998	3.8	4.2	7.7	6.2	80.6–86.6