Table 1 Rate constants and t₉₀ values for thiamine in solutions of TMN and TClHCl

3

TMN

HNO₃

k_obs (day⁻¹)

–

–

0.00243 ± 5e-5^C

0.0082 ± 5e-4^B

0.0250 ± 6e-4^C

R²

–

–

0.9894

0.9340

0.9897

t₉₀ (days)

–

–

43.3 ± 0.9^a

12.9 ± 0.7^c

4.2 ± 0.1^e

k_obs (day⁻¹)

–

–

0.00251 ± 6e-5^C

0.0061 ± 4e-4^B

0.0207 ± 8e-4^C

R²

–

–

0.9847

0.9206

0.9710

t₉₀ (days)

–

–

42 ± 1^ab

17 ± 1^a

5.1 ± 0.2^cd

HCl

k_obs (day⁻¹)

–

–

0.00253 ± 9e-5^C

0.0084 ± 4e-4^B

0.0253 ± 5e-4^C

R²

–

–

0.9664

0.9598

0.9920

t₉₀ (days)

–

–

42 ± 2^abc

12.5 ± 0.5^c

4.17 ± 0.09^e

k_obs (day⁻¹)

–

–

0.00249 ± 7e-5^C

0.0069 ± 4e-4^B

0.0208 ± 3e-4^C

R²

–

–

0.9817

0.9349

0.9950

t₉₀ (days)

–

–

42 ± 1^ab

15.2 ± 0.9^b

5.06 ± 0.08^d

TClHCl

HNO₃

k_obs (day⁻¹)

–

–

0.00246 ± 5e-5^C

0.0068 ± 4e-4^B

0.0177 ± 6e-4^C

R²

–

–

0.9893

0.9283

0.9829

t₉₀ (days)

–

–

42.8 ± 0.9^ab

15.4 ± 0.9^b

6.0 ± 0.2^b

k_obs (day⁻¹)

–

–

0.00268 ± 8e-5^C

0.0068 ± 3e-4^B

0.0160 ± 4e-4^C

R²

–

–

0.9783

0.9657

0.9900

t₉₀ (days)

–

–

39 ± 1^cd

15.5 ± 0.6^b

6.6 ± 0.2^a

HCl

k_obs (day⁻¹)

–

–

0.00275 ± 6e-5^C

0.0088 ± 4e-4^B

0.0245 ± 6e-4^C

R²

–

–

0.9896

0.9584

0.9918

t₉₀ (days)

–

–

38.3 ± 0.8^d

12.0 ± 0.5^c

4.3 ± 0.1^e

k_obs (day⁻¹)

–

–

0.00259 ± 9e-5^C

0.0068 ± 3e-4^B

0.0195 ± 6e-4^C

R²

–

–

0.9674

0.9638

0.9837

t₉₀ (days)

–

–

41 ± 1^bcd

15.5 ± 0.6^b

5.4 ± 0.2^c

6

TMN

HNO₃

k_obs (day⁻¹)

0.00111 ± 4e-5^B

0.00149 ± 6e-5^C

0.022 ± 1e-3^C

0.043 ± 2e-3^B

0.122 ± 4e-3^B

R²

0.9712

0.9446

0.9330

0.9518

0.9883

t₉₀ (days)

95 ± 3^c

70. ± 3^b

4.7 ± 0.3^e

2.5 ± 0.1^d

0.86 ± 0.03^f

k_obs (day⁻¹)

0.0058 ± 4e-4^A

0.023 ± 2e-3^A

0.31 ± 3e-2^A

0.43 ± 6e-2^A

0.48 ± 4e-2^A

R²

0.9261

0.9431

0.9312

0.8945

0.9464

t₉₀ (days)

18 ± 1^d

4.6 ± 0.4^c

0.34 ± 0.03^f

0.24 ± 0.03^e

0.22 ± 0.02^g

HCl

k_obs (day⁻¹)

0.00067 ± 5e-5^B

0.00133 ± 7e-5^C

0.0196 ± 7e-4^C

0.040 ± 1e-3^B

0.129 ± 5e-3^B

R²

0.8943

0.9199

0.9771

0.9820

0.9803

t₉₀ (days)

160 ± 10^a

79 ± 4^a

5.4 ± 0.2^e

2.63 ± 0.09^d

0.82 ± 0.03^f

k_obs (day⁻¹)

0.0058 ± 3e-4^A

0.023 ± 2e-3^A

0.29 ± 3e-2^AB

0.40 ± 5e-2^A

0.44 ± 6e-2^A

R²

0.9259

0.9434

0.9238

0.9051

0.8809

t₉₀ (days)

18 ± 1^d

4.6 ± 0.4^c

0.37 ± 0.03^f

0.26 ± 0.03^e

0.24 ± 0.03^g

TClHCl

HNO₃

k_obs (day⁻¹)

0.00080 ± 3e-5^B

0.00129 ± 5e-5^C

0.019 ± 1e-3^C

0.046 ± 1e-3^B

0.098 ± 8e-3^BC

R²

0.9616

0.9621

0.9422

0.9918

0.9244

t₉₀ (days)

131 ± 5^b

82 ± 3^a

5.5 ± 0.3^e

2.28 ± 0.05^d

1.08 ± 0.09^f

k_obs (day⁻¹)

0.0058 ± 4e-4^A

0.015 ± 2e-3^B

0.26 ± 4e-2^B

0.39 ± 5e-2^A

0.43 ± 7e-2^A

R²

0.8974

0.8154

0.8243

0.8890

0.8289

t₉₀ (days)

18 ± 1^d

6.8 ± 0.9^c

0.41 ± 0.06^f

0.27 ± 0.04^e

0.24 ± 0.04^g

HCl

k_obs (day⁻¹)

0.00102 ± 6e-5^B

0.00136 ± 5e-5^C

0.019 ± 1e-3^C

0.047 ± 1e-3^B

0.107 ± 3e-3^BC

R²

0.9156

0.9576

0.9334

0.9896

0.9903

t₉₀ (days)

103 ± 6^c

77 ± 3^ab

5.4 ± 0.3^e

2.25 ± 0.06^d

0.99 ± 0.02^f

k_obs (day⁻¹)

0.0058 ± 4e-4^A

0.016 ± 2e-3^B

0.25 ± 4e-2^B

0.38 ± 5e-2^A

0.42 ± 6e-2^A

R²

0.8957

0.8263

0.8293

0.9076

0.8621

t₉₀ (days)

18 ± 1^d

6.7 ± 0.9^c

0.41 ± 0.06^f

0.27 ± 0.03^e

0.25 ± 0.04^g