将异烟肼（INH）药片研碎后分取含2.00 mg INH的药粉，加入20 mL水，用玻棒搅拌2 min，所得溶液用蒸馏水稀释至100.0 mL，分取5.00 mL，离心2 min，分取上清液1.00 mL，用水稀释至10.0 mL，即制得INH样品溶液。取1.00 mL 0.20 mol·L^-1乙酸-乙酸钠缓冲溶液（pH 4.6）、1.50 mL 0.50 g·L^-1 NaB （C₆H₅）₄溶液、2.00 mL 1.00 g·L^-1 CuSO₄溶液，混匀后加入1.00 mL INH样品溶液，用水稀释至10.0 mL，振荡0.5 min，静置反应10 min，INH将Cu （Ⅱ）还原为Cu （Ⅰ），Cu （Ⅰ）与B （C₆H₅）₄^-反应生成CuB （C₆H₅）₄缔合物，并进一步聚集生成缔合微粒，形成具有较强共振光散射信号的固液界面。分取适量上述溶液，置于荧光分光光度计中，在200~700 nm内同步扫描激发（λ_ex）、发射（λ_em）波长（λ_em=λ_ex），读取397 nm处共振散射峰的信号强度I_RSS。同步测定试剂空白，得到I⁰_RSS，以ΔI_RSS（ΔI_RSS=I_RSS-I⁰_RSS）进行定量。结果显示：100倍淀粉、120倍葡萄糖、150倍麦芽糖、200倍蔗糖、600倍NO₃^-，800倍Cl^-、1 000倍K⁺、800倍Zn²⁺不干扰INH的测定；INH的质量浓度在0.010~2.00 mg·L^-1内和对应反应体系ΔI_RSS呈线性关系，检出限（3s/k）为0.004 mg·L^-1；方法用于实际样品分析，所得INH测定值的相对标准偏差（n=5）为1.8%~2.6%，测定值和《中华人民共和国药典》（2020年版）高效液相色谱法的基本一致；按照标准加入法进行回收试验，回收率为97.0%~99.0%。

Isoniazid (INH) drug tablets were ground, and the drug powder containing 2.00 mg of INH was taken. After adding 20 mL of water, the mixture was stirred for 2 min with glass rod. The obtained solution was diluted to 100.0 mL by water. An aliquot (5.00 mL) was taken, and centrifuged for 2 min, and 1.00 mL of the supernatant was taken, and diluted to 10.0 mL by water to prepare the INH sample solution. Then 1.00 mL of 0.20 mol·L^-1 acetic acid-sodium acetate buffer solution (pH 4.6), 1.50 mL of 0.50 g·L^-1 NaB(C₆H₅)₄ solution, and 2.00 mL of 1.00 g·L^-1 CuSO₄ solution were added and mixed, and 1.00 mL of INH sample solution was added. The mixture was diluted to 10.0 mL by water, shaken for 0.5 min, and settled to react for 10 min. INH reduced Cu(Ⅱ) to Cu(Ⅰ), and Cu(Ⅰ) reacted with B(C₆H₅)₄^- to form CuB(C₆H₅)₄ complex, which further aggregated to form associated particles, forming a solid-liquid interface with strong resonance light scattering signal. An appropriate amount of the above solution was taken and placed into a fluorescence spectrophotometer, and synchronously scan was made on excitation (λ_ex) and emission (λ_em) wavelengths in the range of 200-700 nm (λ_ex=λ_em), reading the signal intensity I_RSS of the resonance scattering peak at 397 nm. The reagent blank was analyzed simultaneously to obtain I⁰_RSS, with ΔI_RSS (ΔI_RSS=I_RSS-I⁰_RSS) for quantification. It was shown that 100 times starch, 120 times glucose, 150 times maltose, 200 times sucrose, 600 times NO₃^-, 800 times Cl^-, 1 000 times K⁺, and 800 times Zn²⁺ did not interfere with the determination of INH. Linear relationship between values of the mass concentration of INH and ΔI_RSS of the reaction system was kept in the range of 0.010-2.00 mg·L^-1, with detection limit (3s/k) of 0.004 mg·L^-1. The proposed method was used for the analysis of actual samples, and RSDs (n=5) of the INH determined values were found in the range of 1.8%-2.6%. The determined values were basically consistent with those obtained from the high performance liquid chromatography in the Pharmacopoeia of the People's Republic of China (2020 version). Test for recovery was conducted according to the standard addition method, giving recoveries in the range of 97.0%-99.0%.