Table 3.

The results of acute toxicity testing of Fe₃O₄@Au composite MNPs

Group	Dosage		n	Death number	Death rate (p)	Survival rate (q)	p × q
	g · kg−1	Logarithm
1	1.77	0.249	10	0	0	1.0	0
2	2.51	0.399	10	0	0	1.0	0
3	3.54	0.549	10	2	0.2	0.8	0.16
4	5.00	0.699	10	2	0.2	0.8	0.16
5	7.06	0.849	10	4	0.4	0.6	0.24
6	9.98	0.999	10	5	0.5	0.5	0.25
7	14.09	1.149	10	7	0.7	0.3	0.21
8	19.89	1.299	10	10	1.0	0	0
		i = 0.15			∑p = 3.0

Notes: lg LD₅₀ = X_k – I(∑p – 0.5) = 1.299 – 0.15 (3.0 – 0.5) = 0.924; s_m = i × (∑pq/n)^1/2 = 0.15 × 0.36 = 0.054; lg LD₅₀ and its 95% CI were 0.924 ± 1.96 × 0.054 = 0.924 ± 0.106; LD₅₀ and its 95% CI were 8.39 g/kg (6.58–10.72 g/kg).

Abbreviations: LD₅₀, median lethal dose; MNPs, magnetic nanoparticles.