What concentration of acetaldehyde in the sample causes interference in the Total Sulfite Assay Kit (K-TSULPH & K-SULPH)?

Modified on Fri, 24 Sep, 2021 at 11:23 AM

Interference by acetaldehyde is observed when the acetaldehyde concentration is higher than approximately 250 mg/L in the 0.05 mL sample using the TSO₂ Manual Assay Procedure (see Table 1).
At acetaldehyde concentrations higher than 250 mg/L the total sulphite reaction is slower than stated in the TSO₂ Manual Assay Procedure but generates the expected absorbance change when the reaction is allowed to complete. At a concentration of 1250 mg/L acetaldehyde in the sample, the TSO₂reaction takes ~ 15 minutes to complete (at 25°C).

TABLE 1. Acetaldehyde Interference in the TSO₂ Manual Assay. Reactions were performed using the TSO₂ Manual Assay Procedure in 1 cm path-length cuvettes at 25°C.

[Acetadehyde]

(mg/L)

[SO₂]

mg/L

ΔA_totalSO₂

% error

300

0.042

1.477

1.435

0.0

300

0.041

1.458

1.417

1.3

300

0.042

1.502

1.460

-1.7

125

300

0.042

1.498

1.456

-1.4

250

300

0.041

1.466

1.425

0.7

625

300

0.042

1.347

1.305

9.1

1250

300

0.045

0.279

0.234

83.7

Product Page (K-TSULPH)

Product Page (K-SULPH)