Figure 8 Demonstration of chemical noise produced by amine derivatization coupled with gradient elution. (A) Blank of deionized, HPLC-grade water without intentionally added amines after OPA-buSH derivatization. (B) Blank after derivatization and scavenging using IAA followed by cysteic acid/sulfite. (C) 25 nM amino acid standard derivatized as in (B). All sample injection volumes were 100 nL from a 500 µL sample. Chromatography was performed using a 48 µm×40 cm packed capillary column (5 µM Alltima C8) and a linear, binary gradient of mobile phase A (50 mM phosphate pH 6.8w/1 mM

DOI link for Figure 8 Demonstration of chemical noise produced by amine derivatization coupled with gradient elution. (A) Blank of deionized, HPLC-grade water without intentionally added amines after OPA-buSH derivatization. (B) Blank after derivatization and scavenging using IAA followed by cysteic acid/sulfite. (C) 25 nM amino acid standard derivatized as in (B). All sample injection volumes were 100 nL from a 500 µL sample. Chromatography was performed using a 48 µm×40 cm packed capillary column (5 µM Alltima C8) and a linear, binary gradient of mobile phase A (50 mM phosphate pH 6.8w/1 mM

Figure 8 Demonstration of chemical noise produced by amine derivatization coupled with gradient elution. (A) Blank of deionized, HPLC-grade water without intentionally added amines after OPA-buSH derivatization. (B) Blank after derivatization and scavenging using IAA followed by cysteic acid/sulfite. (C) 25 nM amino acid standard derivatized as in (B). All sample injection volumes were 100 nL from a 500 µL sample. Chromatography was performed using a 48 µm×40 cm packed capillary column (5 µM Alltima C8) and a linear, binary gradient of mobile phase A (50 mM phosphate pH 6.8w/1 mM