样品（0~4.0 mg）置于10 mL比色管中，加入pH 7.64的三羟甲基氨基甲烷-盐酸缓冲溶液1.0 mL和1.00×10^-4mol·L^-1孔雀石绿溶液2.00 mL，稀释至10 mL，反应10 min。呋塞米与孔雀石绿反应生成离子缔合物，使体系的瑞利光散射（RLS）发生猝灭作用，最大瑞利光散射峰位于370 nm处。呋塞米的质量浓度在0.006~0.40 mg·L^-1范围内与对应的瑞利光散射猝灭程度（ΔI_RLS）呈线性关系，检出限（3s/k）为0.005 4 mg·L^-1。按标准加入法进行回收试验，回收率为98.7%~102%，相对标准偏差（n=6）均小于3.0%。

The sample (0-4.0 mg) was placed into 10 mL colorimetric tube, and trihydroxymethyl aminomethane-HCl buffer solution of pH 7.64 (1.0 mL) and 1.00×10^-4mol·L^-1 malachite green solution (2.00 mL) were added. The obtained solution was diluted to 10 mL and reacted for 10 min. Furosemide reacted with malachite green to form an ionic association complexes, which led system's Rayleigh light scattering (RLS) had a quenched effect. The maximum RLS peak was located at 370 nm. Linear relationship between RLS quenched degree (ΔI_RLS) and mass concentration of furosemide was found in the range of 0.006-0.40 mg·L^-1, with detection limit (3s/k) of 0.005 4 mg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 98.7%-102%, with RSDs (n=6) all less than 3.0%.