Application of inductively coupled plasma–mass spectrometry for trace element characterisation of equine meats

Figures & data

Table 1. Description of the samples collected in this study.

Sample	Geographic origin	Slaughter age (months)	Gender
1	Scanno (l’Aquila, Italy)	8	M
2	Kazinowo (Poland)	21	M
3	Kazinowo (Poland)	19	M
4	Sokoly (Poland)	12	M
5	Wysokie Mazowieckie (Poland)	11	M
6	Wysokie Mazowieckie (Poland)	10	M
7	Wysokie Mazowieckie (Poland)	12	F
8	Vinchiaturo (Campobasso, Italy)	4	F
9	Anversa degli Abruzzi (l’Aquila, Italy)	10	F
10	Wysokie Mazowieckie (Poland)	15	M
11	Wysokie Mazowieckie (Poland)	10	M
12	Wysokie Mazowieckie (Poland)	15	F
13	Frosolone (Isernia, Italy)	8	F
14	Wysokie Mazowieckie (Poland)	9	M
15	Kazinowo (Poland)	19	F
16	Wysokie Mazowieckie (Poland)	7	F
17	Vinchiaturo (Campobasso, Italy)	10	F
18	Przasnysz (Poland)	13	M
19	Przasnysz (Poland)	13	M
20	Wysokie Mazowieckie (Poland)	17	F
21	Genazzano (Rome, Italy)	7	M
22	Wysokie Mazowieckie (Poland)	22	F
23	Wysokie Mazowieckie (Poland)	19	M
24	Wysokie Mazowieckie (Poland)	12	M
25	Wysokie Mazowieckie (Poland)	12	F
26	Wysokie Mazowieckie (Poland)	12	M
27	Wysokie Mazowieckie (Poland)	11	M
28	Ateleta (l’Aquila, Italy)	60	F
29	Wysokie Mazowieckie (Poland)	21	F
30	Wysokie Mazowieckie (Poland)	13	M
31	Wysokie Mazowieckie (Poland)	12	M
32	Agosta (Rome, Italy)	5	M
33	Wysokie Mazowieckie (Poland)	21	F
34	Wysokie Mazowieckie (Poland)	61	M
35	Wysokie Mazowieckie (Poland)	13	M
36	Ponzano (Rome, Italy)	10	M
37	Wysokie Mazowieckie (Poland)	15	M
38	Wysokie Mazowieckie (Poland)	13	F
39	Wysokie Mazowieckie (Poland)	13	F
40	Gravina (Bari, Italy)	24	F
41	Wysokie Mazowieckie (Poland)	12	M
42	Wysokie Mazowieckie (Poland)	15	F
43	Wysokie Mazowieckie (Poland)	27	M
44	Jenne (Rome, Italy)	11	M
45	Wysokie Mazowieckie (Poland)	18	M
46	Wysokie Mazowieckie (Poland)	13	F
47	Wysokie Mazowieckie (Poland)	14	M
48	Camerata Nova (Rome, Italy)	10	M
49	Wysokie Mazowieckie (Poland)	25	F
50	Wysokie Mazowieckie (Poland)	23	M
51	Wysokie Mazowieckie (Poland)	12	M
52	Scanno (l’Aquila, Italy)	12	M

Table 2. Validation parameters of ICP-MS analytical method.

	Calibration range (ng mL^−1)	Determination coefficient (R^2)	RSD (%) (n = 10)	LOQ (ng g^−1)
Non-essential trace elements
Hg	0.01–0.20	0.9986	8.4	1.5
Pb	1.0–20	0.9982	5.7	2.5
Cd	1.0–20	0.9999	5.3	0.44
Tl	0.01–0.20	0.9994	4.5	0.028
U	0.01–0.20	0.9999	4.0	0.015
Sb	0.10–2.0	0.9990	5.7	0.81
Sn	1.0–20	0.9991	8.5	2.9
Cr	1.0–20	0.9980	7.2	1.2
Ni	1.0–20	0.9875	5.9	20
As	1.0–20	0.9987	9.5	4.2
Sr	40–1000	0.9995	2.1	9.2
Al	5.0–100	0.9997	7.1	350
Be	0.01–0.20	0.9971	8.7	0.71
Essential trace elements
Mo	1.0–20	0.9992	4.1	1.5
V	1.0–20	0.9891	7.8	0.25
Co	1.0–20	0.9981	6.4	0.54
Se	1.0–20	0.9979	5.9	4.7
Mn	5.0–100	0.9980	3.7	42
Cu	5.0–100	0.9987	2.1	10
Zn	40–1000	0.9986	2.9	880
Fe	40–1000	0.9981	3.2	1100
Ca	40–1000	0.9980	3.7	1500

RSD: relative standard deviation; LOQ: limit of quantification.

Table 3. Trace elements in 52 samples of equine meat with statistical descriptors: range, average, and standard deviation (SD).

	Range (ng g^−1)	Average ± SD (ng g^−1)
Non-essential trace elements
Hg	1.5^a–16.2	1.48 ± 2.1
Pb	2.5^a–30.3	5.99 ± 5.0
Cd	2.65–71.2	11.3 ± 12.6
Tl	0.067–0.550	0.164 ± 0.08
U	0.084–0.436	0.218 ± 0.10
Sb	0.81^a–1.10	0.589 ± 0.09
Sn	2.9^a–81.1	15.0 ± 15
Cr	7.24–49.4	21.0 ± 12
Ni	29.4–1073	171 ± 166
As	4.2^a–32.1	7.76 ± 5.0
Sr	44.9–285	132 ± 48
Al	350^a–4090	1040 ± 670
Be	0.71^a–0.71^a	n.a.
Essential trace elements
Mo	6.77–24.1	14.7 ± 3.8
V	0.25^a–14.4	4.47 ± 2.6
Co	0.54^a–3.82	1.87 ± 0.71
Se	16–238	85.2 ± 49
Mn	42^a–127	82.0 ± 21
Cu	0.550^b–2.55^b	1.13^b ± 0.41^b
Zn	31.7^b–75.3^b	48.1^b ± 9.0^b
Fe	15.7^b–46.7^b	25.1^b ± 6.6^b
Ca	22.9^b–104^b	53.9^b ± 18.5^b

^aLOQ (limit of quantification) values are listed in Table 2.

^bValues expressed as micrograms per gram.

Figure 1. A comparison of Ca, Fe, Zn, and Cu levels among meats of different origin.

Figure 2. Element-by-element comparison between meats from equine of different genders.

Figure 3. Element-by-element comparison between equine meats from different breeding geolocations.

Figure 4. Trace element accumulation.

Figure 5. Correlation between levels of Zn/Fe (A) and Fe/Ca (B).

Figure 6. Comparison of equine and bovine meats – principal component analysis: 22 trace elements (A); 8 significant trace elements (p < 0.005) (B).

Table 4. Trace elements in 52 samples of equine liver with statistical descriptors: range, average, and standard deviation (SD).

	Range (ng g^−1)	Average ± SD (ng g^−1)
Non-essential trace elements
Hg	1.5^a–30.0	3.57 ± 4.8
Pb	16.1–1910	151 ± 320
Cd	5.09–2068	675 ± 480
Tl	0.190–0.765	0.343 ± 0.12
U	0.070–1.40	0.197 ± 0.22
Sb	0.81^a–17.7	4.08 ± 3.4
Sn	2.9^a–85.9	11.1 ± 17
Cr	5.59–48.8	15.0 ± 7.7
Ni	20^a–957	121 ± 140
As	4.2–15.6	6.73 ± 3.0
Sr	48.8–762	142 ± 110
Al	247–3331	1080 ± 590
Be	0.71^a–4.98	0.668 ± 0.68
Essential trace elements
Mo	21.3–3929	1888 ± 520
V	1.70–260	20.2 ± 40
Co	1.90–99.5	56.8 ± 20
Se	83.5–636	292 ± 140
Mn	75.7–3920	2140 ± 610
Cu	1.40^b–41.1^b	9.31^b ± 7.6^b
Zn	34.0^b–162^b	69.3^b ± 23^b
Fe	5.97^b–1120^b	359^b ± 270^b
Ca	38.5^b–99.8^b	66.9^b ± 13^b

^aLOQ: limit of quantification) values are listed in Table 2.

^bValues expressed as micrograms per gram.