Automated procedure for determination of ammonia in concrete with headspace single-drop micro-extraction by stepwise injection spectrophotometric analysis

• A stepwise injection headspace single-drop micro-extraction (SWIA-HSDME) system was proposed.
• SWIA-HSDME system is as a versatile approach for automated determination of volatile compounds.
• SWIA-HSDME system was successfully demonstrated in ammonia determination in concretes.
• The problem of significant influence of complex matrices was completely avoided.

A novel automatic stepwise injection headspace single-drop micro-extraction system is proposed as a versatile approach for automated determination of volatile compounds. The system application is demonstrated for ammonia determination in concrete samples. An ammonia gas was produced from ammonium ions and extracted on-line into 5 μL 0.1 M H3PO4 to eliminate the interference effect of concrete species on the ammonia stepwise injection spectrophotometric determination. The linear range was 0.1–1 mg kg−1 with LOD 30 µg kg−1. The sample throughput was 4 h−1. This system has been successfully applied for the determination of ammonia in concretes.

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