针对采用标准方法LY/T 1266-1999或NY/T 1121.15-2006中的硅钼蓝分光光度法检测土壤有效硅时浸提时间长以及检测结果易受显色时间、显色温度和土壤酸度影响等问题，进行了题示研究。在塑料瓶中加入5.00 g样品和0.025 mol·L^-1柠檬酸溶液50.00 mL，盖好瓶塞，摇匀后在300 W超声功率下于30℃浸提2.0 h。浸提液用定性滤纸过滤，滤液引入电感耦合等离子体原子发射光谱仪，在射频功率1 150 W、雾化气流量0.55 L·min^-1、分析谱线251.611 nm条件下测定土壤有效硅含量。结果显示：硅质量浓度在100.0 mg·L^-1以内与响应强度呈线性关系，检出限（3s）为0.012 mg·kg^-1。方法用于19种不同酸度土壤标准物质的分析，测定值均在认定值的不确定度范围内，测定值的相对标准偏差（n=12）均小于10%，且方法和标准方法硅钼蓝分光光度法没有显著性差异，可用于大批量不同酸度土壤中有效硅含量的准确、快速测定。

The study mentioned by the title was conducted for problems including long soaking extraction time and susceptibility of detection results to chromogenic time, chromogenic temperature, and soil acidity by silicon molybdenum spectrophotometry in standard methods of LY/T 1266-1999 or NY/T 1121.15-2006 to detect the available silicon in soil. The 5.00 g of sample and 50.00 mL of 0.025 mol·L^-1 citric acid solution were added into a plastic bottle. After capping the bottle and vortexing, the above mixture was extracted at 30℃ for 2.0 h under 300 W ultrasound power. The extract was filtered with qualitative filter paper, and the filtrate was introduced into the inductively coupled plasma atomic emission spectrometer. The available silicon in soil was determined at the conditions of radio frequency power of 1 150 W, atomizing gas flow of 0.55 L·min^-1, and analytical spectral line of 251.611 nm. As found by the results, linear relationship between values of the mass concentration and response intensity of silicon was kept within 100.0 mg·L^-1, and detection limit (3s) was 0.012 mg·kg^-1. The proposed method was used for the analysis of 19 soil reference materials with different acidity, giving determined values within the uncertainty ranges of the certified values, and RSDs (n=12) of the determined values less than 10%. There was no significant difference between the proposed method and silicon molybdenum spectrophotometry given by the above standard methods, indicating the proposed method was suitable for accurate and rapid determination of available silicon in large batches of soil with different acidity.