SPIFAN Nutrients ERP Book_9-29-15

FOS-04 FOR ERP USE ONLY DO NOT DISTRIBUTE

Table 2-4 Method comparison

997.08 1

999.03 2

New method

Reference 3

Number of sample preparations and analyses needed to complete testing

1

3

3

1

Instrument Run time (min)

45

83x3=249

NAP

65

Can test samples with sucrose:fructan ratio >3:1 Requires post-column reagent addition

Yes

No

Yes

Yes

No

No

NAP

Yes

Applicable to FOS, oligofructose, and inulin

Yes

Yes*

Yes*

Yes

Requires extraction step

No No No

Yes

Yes

Yes Yes Yes

Requires SPE

No No

No No

Requires dry-down

Requires knowledge of commodity type for accurate results**

Yes

Yes

Yes

Yes

Method bias for any commodities

No

No

Yes

No

Uses borate trap

Yes

No

No

No

0.03% (90.8-115% recovery)

0.014% (83-101% recovery)

LOQ (% on RTF basis)

0.5%

0.5%

%RSD (Intermediate Precision?)

2.04-7.12%

5.79%

1.25%

4.22-8.37%

1 Stated method performance taken from Covance labs website effective 10/15/2010. 2 Stated method performance taken from Covance labs website effective 01/21/2005.

*Method accuracy compromised by usage of set DP factors of 4 and 10 (actual range is from 3.7-30). **Limits utility at a regulatory level where the type of material may be unknown or testing for off-label adulteration may be desired. The new method circumvents this via the qualitative ID methodology in the Appendix. Reference #3 is pursuing an alternate method to circumvent this problem.

Conceptually this methodology is the similar to that of Cuany, et. al. (3) However several time savings are gained from the elimination of extraction, SPE, and sample dry-down. An additional time savings is generated in a shorter instrument cycle time (45 minutes versus 65 minutes). Some of this is due to the incorporation of a borate trap to the analysis in place of a standard PA1 guard. Borate negatively impacts HPAEC-PAD chromatography, creating peak distortion and other issues previously observed (3, 5). Furthermore, the addition of the internal standard (as suggested in 997.08) allows for a non-volumetric dilution and a subsequent improvement in LOQ.

1. Linearity – For the 43 standard curves examined no calibration errors greater than + 5% were observed (see figure 2-3). As expected the largest errors were observed in the lowest level standards. However the pattern of errors does not indicate any systematic trends.

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