Table 1.

Blank corrected^a recovery of 10 mg kg⁻¹ SO₂ spikes from various matrices by three different analytical methods (n = 3).

Matrix	OMWb titration	LC-MS/MS	2× MWc
Water	90 ± 3d	108 ± 7	17 ± 1
Fresh garlic	31 ± 16	125 ± 1	42 ± 9
Roasted garlic	34 ± 8e	116 ± 1	Not analysedf
Hummus	42 ± 4	107 ± 1	Not analysed
White grape juiceg	87h	98 ± 7	Not analysed
Dried apricot	86	96 ± 4	Not analysed

Notes:

^aTriplicate analyses of a blank were conducted for each of the matrices. The spiked recovery value was corrected based on these values. All recoveries are expressed as per cent.

^bOptimised Monier–Williams.

^cDouble bubbler Monier–Williams (Lafeuille et al. 2007).

^dValues are reported as mean per cent recovery ± standard deviation for triplicate measurements.

^en = 4 for OMW-roasted garlic analysis.

^fAfter low recoveries were observed on the water and fresh garlic, no analysis was conducted on the remaining matrices.

^gThe white grape juice and dried apricot recovery was previously published (Robbins et al. 2015) and is included for comparison between the problematic and the previously validated matrices.

^hThe white grape juice and dried apricot OMW titration recovery was completed only once. The values are included only as a reference point.