Taylor P J, Salm P, Pillans P I
Department of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, Australia.
J Anal Toxicol. 2001 Sep;25(6):456-60. doi: 10.1093/jat/25.6.456.
We report the validation of a quantitative method for paraquat in plasma and urine using high-performance liquid chromatography (HPLC) with ultraviolet detection (260 nm). Furthermore, we illustrate the use of this method in the clinic (over five years), in conjunction with a qualitative urine paraquat screen. Urine or plasma sample (1 mL) preparation was performed in duplicate using C18 solid-phase extraction. Chromatographic separation was achieved on a Zorbax RX-Silica column (250 x 4.6-mm i.d.). The mobile phase consisted of 96% sodium chloride (5 g/L) and 4% acetonitrile (pH 2.2) pumped at 1.0 mL/min. Using a single-point calibration (1.0 mg/L), the method was found to be linear from 0.1 to 5.0 mg/L. The accuracy and imprecision of the method, over the linear range and for plasma and urine, were 94.7-104.9% and < 12.2%, respectively. The limit of quantitation for both matrices was 0.1 mg/L. The absolute recovery of paraquat from plasma and urine was 79.9 +/- 5.3% and 88.2 +/- 5.3%, respectively. From January 1995 to February 2000, 47 qualitative urine paraquat screens were requested throughout Australia. Nine screens were positive, and eight were confirmed to have paraquat present by our HPLC method. One sample was not analyzed by HPLC because the patient died prior to analysis. Thus, no false-positive results were reported for the qualitative urine screen. An additional 11 samples were referred for patients with positive screens from other sites for HPLC confirmation. The presence of paraquat was confirmed in nine of these samples. In conclusion, a qualitative urine screen combined with our validated HPLC confirmation is an effective protocol for assessing suspected cases of paraquat poisoning.
我们报告了一种采用高效液相色谱法（HPLC）及紫外检测（260nm）测定血浆和尿液中百草枯定量方法的验证情况。此外，我们还阐述了该方法在临床（超过五年）与定性尿液百草枯筛查相结合的应用。尿液或血浆样本（1mL）采用C18固相萃取法一式两份进行制备。在Zorbax RX - 硅胶柱（250×4.6mm内径）上实现色谱分离。流动相由96%氯化钠（5g/L）和4%乙腈（pH 2.2）组成，以1.0mL/min的流速泵入。采用单点校准（1.0mg/L），该方法在0.1至5.0mg/L范围内呈线性。该方法在血浆和尿液的线性范围内的准确度和不精密度分别为94.7 - 104.9%和<12.2%。两种基质的定量限均为0.1mg/L。百草枯从血浆和尿液中的绝对回收率分别为79.9±5.3%和88.2±5.3%。1995年1月至2000年2月期间，澳大利亚各地共进行了47次定性尿液百草枯筛查。其中9次筛查呈阳性，通过我们的HPLC方法确认有8次尿液中存在百草枯。有1个样本未进行HPLC分析，因为患者在分析前死亡。因此，定性尿液筛查未报告假阳性结果。另外有11个来自其他机构筛查呈阳性的患者样本被送来进行HPLC确认。其中9个样本确认存在百草枯。总之，定性尿液筛查与我们经验证的HPLC确认相结合是评估疑似百草枯中毒病例的有效方案。
