AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

Fluor-03 (Feb. 2019) FOR ERP USE ONLY DO NOT DISTRIBUTE

Flow rate eluent (mL/min) Column temperature (°C) Temperature detector (°C)

0.8

45 50

Recording time (min)

10.0

Run time including column clean-up with eluent gradient and sample path cleaning (min)

65

Injection volume (uL)

20

Data source

Conductivity detector

Channel

Conductivity

Temp. coefficient (%/°C)

2.3

Polarity Degasser

+

On

MSM MCS

Automatic stepping

On

Inline Sample Preparation

Dialysis

Table 5 IC gradient program

Time (min) % Eluent A % Eluent B

Curve

0

100 100

0 0

9.9

Linear

10

20 20

80 80

Step

17.5 17.6

Linear

100 100

0 0

Step

60

Linear

(c) Inline dialysis. —Inline dialysis is an effective sample preparation technique for complex sample matrices. With the Metrohm Inline Dialysis technique [1] not only particles are separated from their dissolved analytes, but also colloids, oils components, and large molecules, which lead to column alteration and clogging. Also samples containing proteins can be injected directly after dialysis. Time can be saved by avoiding manual steps such as precipitation of proteins by the Carrez reagent. The patented stopped-flow Dialysis principle (European Patent 0 820 804, US Patent 5,861,097) is as following: Sample is continuously pumped on the sample side (the left side of the membrane). After a rinsing phase, the acceptor stream to the right of the membrane is stopped. Because of the concentration gradient, the ions pass through the membrane until an equilibrium is achieved and thus the concentration in the acceptor solution matches the concentration of the original sample. Afterwards, the acceptor solution is injected directly into the IC.

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