不同添加剂处理样本对高效液相色谱法测定血氯氮平及其代谢产物浓度的影响

目的探讨使用肝素钠抗凝剂、促凝剂、分离胶等添加剂处理的样本是否适合使用高效液相色谱（HPLC）法监测氯氮平（CZP）及其代谢产物去甲氯氮平（N-CZP）浓度。方法选择临床服用CZP治疗达稳态的住院患者,使用真空采血系统分别采集普通管血液样本和含有肝素钠抗凝剂、促凝剂、分离胶等添加剂的样本,在HP-1100 HPLC仪上测定CZP、N-CZP浓度,比较结果的差异。结果不同方式处理的样本间CZP、N-CZP浓度差异有统计学意义（P均〈0.001）。其中普通管血清、肝素钠抗凝血浆、促凝剂处理的血清之间CZP、N-CZP浓度均无差异（P〉0.05）;分离胶处理的样本与普通管血清、促凝剂和肝素钠抗凝剂处理的样本之间CZP、N-CZP浓度差异均有统计学意义（P〈0.01~0.001）。在不分离凝块情况下,4℃和室温放置24 h后,分离胶处理的样本CZP、N-CZP浓度均低于放置前（P〈0.05）,其他方式处理的样本结果差异无统计学意义（P〉0.05）。分离血清4℃放置24 h后,分离胶处理的样本CZP浓度低于放置前（P〈0.05）,而N-CZP浓度升高（P〈0.05）;促凝剂处理的样本CZP、N-CZP浓度均降低（P〈0.05）;其他方式处理的样本差异无统计学意义（P〉0.05）。结论促凝剂和肝素钠处理样本适用于CZP、N-CZP的快速测定,但使用促凝剂处理的样本,最好能及时测定,不能及时测定的应在不分离血凝块的条件下保存;分离胶处理的样本不适合使用HPLC法测定CZP、N-CZP浓度,也不适于储存和运输样本。

Influence of different additives to the concentrations of clozapine and its metabolite in blood samples measured by high performance liquid chromatography

Objective To explore the feasibility of determining the concentrations of elozapine （CZP） and norclozapine （N-CZP） in blood samples treated with various additives by high performance liquid chromatography （HPLC）. Methods The blood samples of patients treated with CZP which has reached a steady state were collected in four different vacuum tubes：one no additive, and 3 tubes with heparin sodium anti-coagulant, coagulant, separation gel, respectively. The CZP and N-CZP concentrations were determined by HPLC （Model HP-1100）. The differences of the results were compared. Results There were significant differences in CZP and N-CZP concentrations among four types of samples （Χ^2 =25. 600, P 〈 0. 001; Χ^2 = 32. 000, P 〈 0. 001 ）. CZP and N-CZP concentrations had no difference among common serum, heparin sodium anti-coagulant plasma and coagulant serum （P 〉 0. 05 ）. There were significant differences in CZP and N-CZP concentrations between sample with seperation gel and the other three samples （P 〈 0. 01- 0. 001 ）. In samples treated with separation gel, without clot separation, both CZP and N-CZP relatively decreased after being stored at room temperature or at 4 ℃ for 24 h（ P 〈0.05） , and the other samples had no difference （P 〉0.05） ; additionally, with serum separation, CZP relatively decreased after being stored at 4℃ for 24 h（ P 〈 0.05 ）, whereas N- CZP increased （P 〈 0.05 ）. Both CZP and N-CZP concentrations in samples with coagulant decreased under the same conditions （P 〈 0.05 ）. The other samples had no significant difference （ P 〉 0.05 ）. Conclusions The samples with coagulant or heparin sodium anti-coagulant are suitable for the quick determination of CZP and N-CZP. However, the samples with coagulant have to be determined promptly; otherwise, the samples should be stored without separating blood clot. The samples with separation gel are not suitable for CZP and N-CZP determination by HPLC, neither for storage nor for transportatio