## 4 Glyphosate and AMPA in Foods
### Detection and Quantification
Additionally, FMOC-Cl has been used as a derivatizing agent during the analysis of GLYP and AMPA from baby formula, bovine liver and kidney [80,120], and oat and rye wheat [121], among others. [PERSON] et al. [59] reported a methodology for the analysis of GLYP and AMPA in honey using FMCO-Cl derivatization prior to LC-MS/MS determination. In this case, two important challenges related to the derivatization process were identified. Firstly, the quite acidic nature of the concentrated honey sample (40% \(w/v\)) reduces the buffering capacity of the sodium tetraborate solution, lowering the final solution pH to 9.0. This suboptimal pH decreases the efficiency of the reaction. To address this problem, a 0.1 M sodium carbonate solution was used to raise the optimal pH value of 9.5, ensuring proper reaction conditions. The second major challenge involves the low concentration of FMOC-Cl (1-10 mg/mL) used in the reaction. At these levels, the amount of derivatizing agent is not enough to fully derivatize the analytes. Honey is a complex matrix rich in amino acids; thus, competitive reactions can occur, reducing the availability of FMOC-Cl for GLYP and AMPA. To overcome this problem, the authors recommend using 0.2 mL of a 50 mg/mL FMOC-Cl solution to guarantee the complete derivatization of the analytes. [PERSON] and [PERSON] [82] developed a method for determining glyphosate, glufosinate, and AMPA in organic soybean and corn using LC-MS/MS. The analytes were separated on a silica-based column and 50 mM ammonium formate as the mobile phase. Different pH values were tested, with 2.6 found to be ideal for glyphosate retention; in addition, higher pH produces more retained and tailing peaks. Fortification levels of 0.1, 0.5, and 2.0 \(\upmu\)g/g were selected for all analytes. Recovery percentages for glyphosate ranged from 89 to 107% in corn, and 96 to 103% in soybean. For AMPA, recovery values were low when no IL-IS was added. However, with the addition of IL-IS, recoveries increased to 96-113% for corn and 101-108% for soybeans. In the analysis of honey, the derivatization of glyphosate faces some challenges: the acidic nature of concentrated honey solutions results in a low efficient buffering capacity of sodium tetraborate solution, keeping the pH lower than necessary for the reaction to have a good yield. In this situation, 0.1 M sodium carbonate (pH = 9.5) works better for glyphosate derivatization [59]. Furthermore, additional derivatizing agents have been employed to enhance the detection and quantification of GLYP and AMPA in food samples. [PERSON] et al. [64] developed an effective protocol that involves the oxidation of GLYP with calcium hypochlorite, followed by a reaction with OPA-MERC to yield a fluorescent derivative with a limit of quantification (LOQ) of 40 \(\upmu\)g/kg and a coefficient of variation of less than 20%. Moreover, [PERSON] et al. [110] used a sensitive pre-column derivatization HPLC method for GLYP and AMPA detection in soybean samples. They used 3,6-dimethoxy-9-phenyl-9H-carbazole- 1-sulfonyl chloride (DPCS-CI) as a labeling agent under alkaline conditions. The LOD was 0.02 and 0.01 ng/mL for GLYP and AMPA, respectively, with recovery values higher than 95%. In this context, the use of derivatization methods constitutes a significant drawback. These reactions typically require extended reaction times, are challenging to control, and may leave residual derivatizing agents in the reaction medium. Additionally, the poor stability of the resulting derivatives often hinders the achievement of the desired levels of accuracy and precision in the analysis [103]. In addition to chromatographic methods, antibody-based immunoassay techniques have been developed to identify and quantify pesticides in food samples. These techniques offer high sensitivity, specificity, and rapid analysis capabilities for routine screening and monitoring of pesticides in complex matrices. Notable examples include enzyme-linked immunosorbent assays and surface plasmon resonance (SPR) biosensors.