# Development of a dual-chamber derivatization method for the determination of cyanide in sodium nitroprusside and its preparation via HS-GC-ECD

## TL;DR

A new method using gas chromatography was developed to accurately measure cyanide in a drug called sodium nitroprusside, which can degrade easily.

## Contribution

A dual-chamber derivatization method was introduced to analyze cyanide in sodium nitroprusside without direct contact.

## Key findings

- The method showed linearity in the range of 0.012–1.56 μg/mL.
- The limit of quantitation was as low as 12.0 ng/mL.
- The method is accurate, precise, and suitable for quality control.

## Abstract

The acute toxicity of cyanide and its pharmaceutical residues has fueled interest in the development of analytical methods for its determination, particularly for sodium nitroprusside (SNP), a widely used vasodilator with potential cyanide residues. In this study, a dual-chamber derivatization bottle was designed to establish an interconnected gas environment, thereby facilitating chloramine T-mediated cyanide conversion to cyanogen chloride (CNCl) without direct contact with SNP. Subsequent determination of the analytes was undertaken using a headspace-gas chromatography-electron capture detector (HS-GC-ECD). The challenges of analyzing cyanide and the rapid degradation of SNP were addressed simultaneously. The method was subjected to rigorous validation, encompassing specificity, linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision, and robustness. The validation process revealed a notable degree of linearity within the range of 0.012–1.56 μg/mL, with a LOQ of 12.0 ng/mL. The method was found to be both accurate and precise, thus satisfying the requisite criteria. This method facilitates reliable cyanide monitoring in degradation-prone pharmaceuticals.

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•An HS-GC-ECD method was developed to quantify cyanide in sodium nitroprusside.•The method exhibited linearity, specificity, precision, and low LOD and LOQ values.•The dual-chamber device was designed to achieve dual-chamber derivatization.•Method is suitable for quality control analysis.

An HS-GC-ECD method was developed to quantify cyanide in sodium nitroprusside.

The method exhibited linearity, specificity, precision, and low LOD and LOQ values.

The dual-chamber device was designed to achieve dual-chamber derivatization.

Method is suitable for quality control analysis.