Table 2.

Concentrations of inorganic ions. Reference normal ranges for human plasma are tallied for comparison; plasma concentrations for Ca⁺⁺ and Mg⁺⁺ represent the free or ionized forms of these ions. The ranges tolerated by P. falciparum cultures are listed as EC₅₀ values as reported [30, 32]. The pH values are unitless.

Ion	RPMI 1640 value, mM	Human plasma value, mM	Reference for human range	Range tolerated by P. falciparum cultures, mM
Na+	142.8	135–145		1.2 to >150
K+	5.4	3.7–5.1		0.17 to >148
Cl−	108.3	95–105		31 to ≥108
Ca+2	0.42	1.03–1.23	[48]	N/D
Mg+2	0.41	0.55 ± 0.05	[49]	N/D
NO3 −	0.84	0.02	[50]	N/D
SO4 −2	0.41	0.3	[51]	N/D
HPO4 −2	5.64	0.8–1.5		0.6 to ≥5.64
HCO3 −	28.6	18–23		N/D
pH	7.2	7.31–7.45		~6.5 to >8