Pathology/Lab Coding Alert

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Count Stationary/Mobile Phases

Question: I-m trying to understand how to code chromatography lab procedures based on stationary phase/mobile phase. Please explain how to code these two scenarios:

1. The lab performs a column chromatography using a single stationary and mobile phase to identify two different unlisted analytes.

2. The lab performs a column chromatography using a single stationary phase and two mobile phases to identify two different unlisted analytes.

Maine Subscriber

Answer: Chromatography is a method that labs use to physically separate components of a complex mixture by distributing the components between two phases. The stationary phase is the substance that is fixed in place, such as silica gel packed into a tube for column chromatography.

The mobile phase is the portion that moves, such as a solvent that carries the mixture components up the column, separating them by physical or chemical properties.

Because running a single mobile phase/stationary phase requires the same amount of work whether the test identifies one or more analytes, chromatography codes often use the stationary phase/mobile phase as the unit of service rather than the analyte.

Solution: For your example 1, report the service as 82492 (Chromatography, quantitative, column [e.g., gas liquid or HPLC]; multiple analytes, single stationary and mobile phase).

For example 2, this constitutes two separate procedures, so you should list two units of 82491 (- single analyte not elsewhere specified, single stationary and mobile phase).