Journal of Spectroscopy

Research Article

Simultaneous Determination of Caffeine and Taurine in Energy Drinks by FT-MIR Spectroscopy Coupled with Multivariate Analysis

Table 1

Taurine and caffeine concentrations in energy drinks.


Energy drink	Taurine (mg 100/mL)	Reported on the label (mg/100 mL)	Caffeine (mg 100/mL)	Reported on the label (mg 100/mL)

1	ND^s	WI	81.29 ± 0.6^x	32
2	69.51 ± 1.4^a	WI	206.26 ± 2.0^r	WI
3	24.34 ± 1.4^bc	WI	223.27 ± 1.1^q	WI
4	27.04 ± 1.2^b	WI	236.40 ± 1.6^p	WI
5	1.88 ± 0.4^qrs	1.45	231.68 ± 0.2^p	WI
6	4.95 ± 0.2^k–r	4.16	34.15 ± 0.6^a-b	80
7	4.95 ± 0.2^k–r	5.82	79.09 ± 0.7^x	80
8	2.74 ± 0.4^o–s	3.09	27.42 ± 1.1^{ac ad}	19.5
9	12.31 ± 0.8^d–g	WI	102.61 ± 1.3^v	WI
10	2.54 ± 1.2^p–s	2.61	57.20 ± 1.8^z	WI
11	6.03 ± 1.1^j–q	7.82	88.27 ± 1.0^w	WI
12	10.28 ± 0.7^e–i	WI	63.57 ± 0.6^y	WI
13	ND^s	WI	386.38 ± 0.3^l	WI
14	12.52 ± 0.6^d–f	WI	101.33 ± 0.3^v	WI
15	4.08 ± 1.6^m–s	4.25	903.47 ± 0.3^c	WI
16	1.03 ± 0.07^r–s	WI	36.77 ± 0.7^a–b	30
17	1.03 ± 0.13^r–s	WI	37.03 ± 0.8^a–b	30
18	1.03 ± 0.07^r–s	WI	14.92 ± 0.5^ae	15
19	22.60 ± 0.04^c	WI	556.28 ± 1.2ⁱ	WI
20	8.85 ± 1.7^f–k	8.42	285.12 ± 1.6ⁿ	WI
21	10.48 ± 0.4^e–i	WI	118.77 ± 1.0^t	WI
22	9.40 ± 0.9^e–j	10.74	32.31 ± 1.1^{ab ac}	19.5
23	8.41 ± 1.3^f–l	9.26	26.66 ± 0.7^ad	19.5
24	ND^s	WI	51.35 ± 0.4^aa	WI
25	1.05 ± 0.04^r–s	1.42	15.24 ± 0.8^ae	WI
26	ND^s	WI	656.80 ± 1.9^h	WI
27	3.64 ± 0.06^n–s	3.72	870.50 ± 0.6^d	WI
28	13.20 ± 1.1^d-e	WI	806.70 ± 0.6^e	WI
29	2.38 ± 0.2^p–s	3.72	764.21 ± 0.8^f	WI
30	8.04 ± 0.4^h–m	7.43	1126.17 ± 5.0^a	WI
31	7.85 ± 0.4^h–n	7.89	766.01 ± 0.4^f	WI
32	26.60 ± 4.3^b-c	WI	16.49 ± 0.1^ae	15
33	11.37 ± 0.5^d–h	WI	979.02 ± 5.6^b	WI
34	7.37 ± 0.8^h–n	7.23	692.89 ± 0.5^g	WI
35	6.43 ± 0.8^i–p	5.41	171.88 ± 0.04^s	WI
36	ND^s	WI	63.55 ± 0.5^y	WI
37	6.82 ± 0.5^i–o	5.43	49.69 ± 1.5 ^aa	WI
38	12.29 ± 0.9^d–g	WI	34.15 ± 0.5^ab	WI
39	10.57 ± 1.9^e–i	WI	32.30 ± 0.7^{ab ac}	WI
40	7.01 ± 1.9^i–n	WI	50.34 ± 1.1^aa	WI
41	9.50 ± 1.6^e–j	WI	66.59 ± 1.4^y	WI
42	7.55 ± 0.9^h–n	WI	108.47 ± 0.8^u	WI
43	8.23 ± 1.03^g–m	WI	87.47 ± 0.05^w	19.5
44	12.59 ± 1.7^d–f	WI	32.29 ± 0.8^{ab ac}	19.5
45	10.58 ± 1.4^e–i	WI	76.43 ± 3.5^x	33
46	4.60 ± 0.6^l–r	3.75	412.46 ± 0.7^j	WI
47	22.75 ± 0.4^c	WI	278.24 ± 0.4^o	WI
48	9.21 ± 1.5^e–j	WI	319.60 ± 0.1^m	WI
49	15.09 ± 0.6^d	WI	386.96 ± 2.8^l	WI
50	25.44 ± 0.9^b-c	WI	398.55 ± 0.8^k	WI

ND: nondetected. WI: without information. Values represent means ± standard deviation. Means with different letters per column are statistically different (Tukey, ).