AOAC SPIFAN Stakeholder Program Meeting Book (August 28, 2021)

Preliminary Interlaboratory Study

SPIFAN III Sample

SPIFAN II Sample

SRM 1869

WPC I

WPC II

Milk/whey/soy IF

Hyd milk IF

Whey Ingr

Whey Ingr

Part hyd soy IF

Type

19.0 % 14.5 %

27.0 % 12.2 %

2.2 % 35 %

25.5 %

Fat

28 %

7.5 %

Protein

Chlorate Mean (ng/g) Chlorate RSD R Perchlorate Mean (ng/g) Perchlorate RSD R

104

265

66.8

1440

328

3.0 %

6.0 %

10.8 %

4.4 %

5.9 %

--

--

--

30.0

5.75

--

--

--

5.8 %

7.1 %

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Preliminary Interlaboratory Study

• Highest RSD R observed at lowest chlorate/perchlorate levels • Most laboratories used LC-MS/MS methods

• No obvious biases other than for one laboratory that did not use labeled ISTD • One laboratory used IC-MS – results poor but laboratory attributed this to sample preparation issues and not instrumental analysis • No observed trends based on laboratory experience • Most participants were manufacturers (50 %) or CROs (40 %) - no government laboratories participated • Laboratories expressed a variety of experience and frequency of testing these types of samples

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