Estimation of Ion Competition via Correlated Responsivity Offset in Linear Ion Trap Mass Spectrometry Analysis: Theory and Practical Use in the Analysis of Cyanobacterial Hepatotoxin Microcystin-LR in Extracts of Food Additives

Table 2

Slopes of the linear fittings and exponents for the exponential fittings. Fittings were carried out for concentration-response dependences for the areas and maximal intensities of the MCYSTLR molecular ion of m/z 995 [M + H]⁺ and the sodium adduct ion of m/z 509 [M+H+Na]²⁺. Manually and automatically obtained values were fitted for all samples (pure MCYSTLR and MCYSTLR in Stigeoclonium sp. extract and salmon hydrolyzate).

		Expertomica			Manual
	Calibration	Salmon	Stigeoclonium	Calibration	Salmon	Stigeoclonium
Linear slope
Area NA adduct	0.10060	4.98100	0.97450	0.10080	3.49100	0.90970
Area molecular ion	0.09800	4.76000	1.03900	0.09802	3.20800	0.98200
Max intensity NA adduct	0.10010	4.37200	0.86500	0.10160	3.99900	0.92120
Max intensity molecular ion	0.10080	3.62500	0.93860	0.09746	3.47800	0.99960
Exp exponent
Area NA adduct	−0.01077	1.00100	−0.31260	−0.02181	1.00100	−0.69510
Area molecular ion	0.06452	0.99960	−0.67920	0.05913	1.00200	−0.66400
Max intensity NA adduct	−0.02063	1.00400	1.26000	−0.04363	1.00100	0.09998
Max intensity molecular ion	−0.00655	0.99900	0.36720	0.07418	0.99950	0.15920