OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

LOD and LOQ were estimated as in the method developer study. The estimated values are presented in Table 21. The tested matrix yielded estimated LOQ values lower than 20 mg/kg for both method ranges.

Table 20. Results obtained by the independent laboratory (all sulfite results expressed in mg/kg)

Experiment Date: 9/21/2017

Experiment Date: 9/22/2017

Sample 4

Sample 1

Sample 5

Sample 2 Sample 3

Portion 1

32

74

112

Portion 1

<10

237

Portion 2

35

73

99

Portion 2

<10

238

Portion 3

33

76

108

Portion 3

<10

244

Monier- Williams Method

Monier- Williams Method

Mean

33

74

106

Mean

-

240

% RSD r

6.1

1.8

6.3

% RSD r

-

1.6

Theoretical level SO2 (mg/kg)

Theoretical level SO2 (mg/kg)

54

107

160

0

317

Recovery ( %)

61

69

66

-

76

Recovery ( %) (Mean /theoretical level)*100

(Mean MW

/theoretical

MW

level)*100

Portion 1

50

97

145

Portion 1

0

253

Portion 2

55

101

145

Portion 2

0

242

Biofish method (30-150 mg/kg range)

Biofish method (30-150 mg/kg range)

Portion 3

55

105

144

Portion 3

0

251

Portion 4

54

105

142

Portion 4

0

249

Portion 5

52

103

141

Portion 5

0

245

Mean

53

102

143

Mean

0

248

R=0.9999 m=- 219486.84 b=-1.53

R=1 m=- 221557.00 b=-0.01

s r

2.2

3.3

1.8

s r

-

4.5

% RSD r

4.1

3.3

1.3

% RSD r

-

1.8

Accuracy (%)

Accuracy (%)

160

138

135

-

103

(mean Biofish

/mean OMA

)*100

(mean Biofish

/mean OMA

)*100

33