固相萃取-气相色谱质谱法测定生物材料中的氯氮平

目的：建立氯氮平的固相萃取．气相色谱质谱(SPE-GC-MS)测定法。方法：血液及肝中的氯氮平用固相萃取柱分离后，以SKF525A为内标，用气相色谱质谱法测定其含量，同时对该法的检测限、线性范围及回收率进行探讨。结果：氯氮平的检测限为0．05ng，线性范围为0．5～100ng，血中平均回收率为90．1％，RSD为8．3％(n=6)。结论：本法检验并测定生物材料中的氯氮平，操作简便，结果准确，重现性好。     

固相微萃取-GC-MS法分析火麻仁挥发油的化学成分

目的:分析火麻仁挥发油的化学成分。方法:采用固相微萃取-气相色谱-质谱法分析火麻仁挥发油化学成分,用峰面积归一化法测定各化学成分的相对百分含量。结果:共分离出54个组分,鉴定了41个组分,其相对含量占挥发油组分总含量的90.07%。结论:本方法快速方便、样品用量少、富集组分多,是一种无需溶剂的环保型分析方法,适用于挥发油的化学成分分析。     

固相萃取-气相色谱串联质谱法测定温莪术中19种有机氯和有机磷农药残留

目的:建立固相萃取-气相色谱串联质谱法测定温莪术中11种有机磷和8种有机氯农药残留,对10种不同批次的温莪术样品进行农药残留测定。方法:温莪术样品用有机溶剂萃取法进行提取,提取溶剂选为乙腈,C18固相萃取小柱净化提取液,用气相色谱-质谱仪分析,采用选择离子模式测定,外标法定量。结果:19种农药成分的峰面积与其质量浓度均有良好的线性关系,相关系数在0.991～1.000。19种农药成分的加标回收率为60.5%～109.3%,RSD为3.9%～10.5%。结论:该方法简便、快速,灵敏度高,重复性好,能够准确地检测温莪术中19种农药残留。     

鱼腥草注射液中挥发性成分的检测方法

目的:建立鱼腥草注射液顶空固相微萃取-气相色谱-质谱联用分离鉴定及含量测定新方法,通过顶空固相微萃取与传统水蒸气蒸馏、固相萃取等提取工艺比较,为改进鱼腥草注射液制备工艺奠定基础。方法:以色谱峰总面积为指标,对萃取头种类等5项顶空固相微萃取关键提取条件进行优化,分别采用顶空固相微萃取、水蒸气蒸馏、固相萃取等3种方法提取鱼腥草注射液中的挥发性成分,通过分离出色谱峰个数、鉴定出化合物数量、精密度等指标比较提取效果。结果:顶空固相微萃取对鱼腥草注射液中挥发性成分的提取效果最佳。结论:顶空固相微萃取具有操作简便、快捷、不污染环境、精密度高等优点,可用于鱼腥草注射液中挥发性成分提取、分析。     

阳离子色谱柱-HPLC法测定人血浆中氯氮平及去甲氯氮平浓度

目的:建立同时测定人血浆中氯氮平及去甲氯氮平浓度的阳离子色谱柱-HPLC法。方法:用强阳离子交换色谱柱-HPLC测定人血浆中氯氮平及去甲氯氮平浓度,色谱柱为强阳离子交换色谱柱(4.6 mm×100 mm,5μm),流动相为乙腈-0.01 mol·L-1磷酸铵溶液(pH 5.1)(60∶40),流速为1.2 mL·min-1,紫外检测波长为257 nm,以AF2672为内标,含氯氮平及去甲氯氮平的血样经C8固相小柱萃取后进样。结果:阳离子色谱柱-HPLC测得氯氮平、去甲氯氮平的色谱峰峰形对称、无内外源性物质干扰,检测结果稳定、可靠、重复性好;通过改变流动相pH易于调整各化合物保留时间,同时去除空白血浆干扰;固相萃取前处理简单、省时且萃取回收率较高。氯氮平及去甲氯氮平浓度在50.4～990 ng·mL-1范围内线性关系良好;氯氮平及去甲氯氮平低(50.4 ng·mL-1)、中(396 ng·mL-1)、高(990 ng·mL-1)3个浓度的萃取回收率均大于91%,日内和日间RSD均小于4%(n=5)。结论:阳离子色谱柱-HPLC法测定人血浆中氯氮平及去甲氯氮平浓度,色谱峰峰形对称,保留时间适宜且无杂质干扰,适用于临床氯氮平及去甲氯氮平血药浓度监测和药动学研究。     

固相微萃取在生物体液分析中的研究进展

固相微萃取是一种无溶剂样品预处理技术。固相微萃取以其无需使用溶剂、样品用量少、有一定的富集作用等特点而受到广大分析工作者的关注。本文着重综述了该方法的装置、原理、影响因素及其应用，尤其是在使用气相色谱—质谱联用、高效液相色谱—质谱联用技术分析生物体液中的应用。     

固相萃取高效液相色谱内标法测定冬虫夏草中甘露醇的含量

目的:研究用固相萃取预分离,高效液相色谱内标法测定冬虫夏草中甘露醇的含量。方法:冬虫夏草样品中的甘露醇用水超声振荡浸取,浸取液用 Waters Sep-Pak-C_(18)固相萃取小柱预分离,以海藻糖为内标物,Waters Sugar-Pak-1(6.5 mm×300 mm)钙型阳离子交换柱为固定相,0.05 g·L~(-1)EDTA 钙钠水溶液为流动相,流速0.5 mL·min~(-1),示差折光仪为检测器测定冬虫夏草样品中的甘露醇含量。结果:最低检测限为2.0μg·mL~(-1);回收率在97%～102%之间,RSD 在0.86%～1.2%之间。结论:方法简便、灵敏、准确、适用于冬虫夏草样品的甘露醇测定。     

LLE-GC-MS法同时测定甘磷酸胆碱中的缩水甘油和3-氯-1,2-丙二醇

目的 建立液液萃取-气相色谱-质谱法(LLE-GC-MS)同时测定甘磷酸胆碱原料药中的基因毒性杂质缩水甘油和3-氯-1,2-丙二醇。方法 采用酸性氯化钠溶液和酸性无水硫酸钠溶液分别处理甘磷酸胆碱原料药，经硅藻土柱净化、富集后用七氟丁酰基咪唑衍生，采用气相色谱-质谱法(SIM模式)进行检测，以D₅-3-氯-1,2丙二醇作为内标，通过双样本差减法计算样品中缩水甘油和3-氯-1,2-丙二醇的含量。结果 2种基因毒性杂质与内标物的峰面积比值在0.1～2 mg·L^-1浓度范围内呈线性相关，相关系数(r)均不小于0.999 2,样品的加样回收率为86.4%～103.3%(RSD<6.0%,n=9)。结论 该方法灵敏度高、专属性强，适用于甘磷酸胆碱原料药中缩水甘油和3-氯-1,2-丙二醇的测定。     

固相微萃取-气相色谱-质谱联用分析云木香挥发油成分

目的:利用固相微萃取-气相色谱-质谱联用技术分析云木香挥发油的化学成分,为云木香的挥发油成分分析提供新方法。方法:固相微萃取法提取挥发油,气相色谱-质谱联用技术对挥发油成分进行分离鉴定,并采用面积归一化法确定各成分的相对质量分数。结果:样品在110℃下平衡30 min,吸附15 min,100μm PDMS纤维头能有效地吸附云木香挥发油成分。GC-MS共鉴定出52个成分,其中相对质量分数较高的有7,10,13-十六碳三烯醛(40.06%)、去氢木香烃内酯(17.60%)、α-芹子烯(4.05%)、α-姜黄烯(4.22%)。结论:云木香挥发油具有丰富的化学成分,固相微萃取-气相色谱-质谱联用能全面快速地获得其组成信息,可应用于云木香挥发油成分的快速分析。     

固相萃取毛细管气相色谱法测定党参、龙胆中15种有机氯农药的残留量

目的用固相萃取毛细管气相色谱分析方法测定党参、龙胆2种中药材中15种有机氯农药残留量。方法样品以混合溶剂超声提取、Florisil固相萃取小柱净化处理后,采用DB 1701毛细管气相色谱柱分离样品,电子捕获检测器检测,内标法定量。结果15种农药在5~500μg.L-1内具有良好的线性关系,相关系数均大于0.995 0。15种农药3个不同质量浓度的平均回收率为83.1%~110.6%,RSD为3.4%~14.8%。最小检测量为0.08~1.50μg.L-1。被测样品中均含有不同程度的有机氯农药。结论本法可用于中草药党参和龙胆中有机氯类农药的残留量测定。     

Differential effects of neuroleptic drugs on the delayed matching-to-sample performance of pigeons

The effects of clozapine, thiothixene, sulpiride, chlorpromazine and loxapine were examined in pigeons responding under a delayed matching-to-sample (DMTS) procedure using 0-, 2- and 8-sec delay intervals. Chlorpromazine (3-100 mg/kg), thiothixene (0.03-1.7 mg/kg), clozapine (0.1-5.6 mg/kg) and loxapine (0.1-10 mg/kg) produced dose-related decreases in the percent of correct responses (accuracy). With the exception of chlorpromazine, the relative magnitude of the accuracy-decreasing effects were unrelated to the length of the delay interval and the nondrug levels of accuracy. In contrast to these accuracy-decreasing effects, sulpiride (3-300 mg/kg) failed to decrease accuracy across the range of doses evaluated. Chlorpromazine, loxapine and clozapine increased response rates at low doses and then decreased response rates as the dose was increased. Thiothixene and sulpiride only decreased response rates in a dose-dependent fashion. The order of potency for the rate-suppressing effects of these drugs was thiothixene greater than clozapine = loxapine greater than chlorpromazine greater than sulpiride. The results of the present investigation suggest that, despite similar dopamine antagonist properties, neuroleptics produce qualitatively different effects in pigeons responding under DMTS procedures.     

Neuroleptic-induced hypersensitivity of striatal dopamine receptors in the rat as a model of tardive dyskinesias. Effects of clozapine,haloperidol, loxapine and chlorpromazine

The present study has compared the abilities of clozapine, haloperidol, chlorpromazine and loxapine to induce dopamine (DA)-receptor hypersensitivity in rats, as measured by the apomorphine response after withdrawal of the antipsychotic drugs. Haloperidol, chlorpromazine and loxapine, but not clozapine, potentiated the apomorphine response during 1–2 weeks after withdrawal. Clozapine, given prior to apomorphine, reduced the responses of the haloperidol and loxapine groups to the control level. The effects of haloperidol and clozapine were quantified in rats with unilateral striatal lesions.Biochemical investigations showed that tolerance developed to the increase in striatal homovanillic acid (HVA) after chronic treatment with haloperidol, chlorpromazine and loxapine, whereas clozapine (20 mg/kg p.o.) failed to affect the HVA content, and no tolerance developed to the increase seen at 80 mg/kg. Cross-tolerance to the rise in HVA was seen with haloperidol, chlorpromazine and loxapine, but chronic pretreatment with clozapine failed to affect the rise in HVA induced by a single dose of the former compounds.On the basis of these results, it is predicted that tardive dyskinesias are unlikely to develop after this drug, and that clozapine may attenuate or abolish neuroleptic-induced tardive dyskinesias.Part of this work was presented at the IXth Congress of the C.I.N.P. in Paris, July 1974.     

Capillary zone electrophoresis determination of meropenem in biological media using a high sensitivity cell

A capillary electrophoresis method with a high sensitivity cell (Z-cell) has been developed for the determination of meropenem in aqueous solution and in biological media (urine, plasma). Water samples were analysed using two calibration curves of meropenem with standard capillary and a capillary with a high sensitivity cell. In urine, the samples were only diluted in buffer and were injected without any further sample preparation. For the analysis of plasma samples, a calibration curve was utilized covering the meropenem concentration range of 0.5–200 μg/ml. The detection limit and the relative standard deviation of the migration times and of the peak areas were determined.     

5个不同地区绞股蓝中挥发性成分的SPME-GC-MS分析

目的:建立固相微萃取-气相色谱质谱方法,对采自4省市5个地区药用植物绞股蓝的挥发性化学成分进行定性定量分析。方法:采用固相微萃取-气相色谱-质谱(SPME-GC-MS)联用技术对绞股蓝挥发性成分进行分析,利用峰面积归一化法测定各个成分的相对百分含量。结果:5个地区的绞股蓝中,总共分离出67个成分,主要含有醛类、酮类、烷烃类、烯烃类、芳香烃类、醇类和脂类。5个样品中共有成分6个,分别为:3,7-二甲基-1,6-辛二烯-3-醇、萘、α-紫罗酮、香叶基丙酮、β-紫罗酮和6,10,14-三甲基-2-十五烷酮。其中平利绞股蓝中含量最高的成分为3-辛酮(14.93%),宁陕鱼洞村绞股蓝中含量最高的为香叶基丙酮(10.8%),湖南麻姑仙境绞股蓝中含量最高的为3,7-二甲基-1,6-辛二烯-3-醇(22.4%),重庆缙云山和四川青城山绞股蓝中含量最高的均为安息香醛,含量分别为63.16%和38.52%。结论:5个地区绞股蓝中挥发性成分差异性很大。     

Human genetic variations in the 5HT2A receptor: a single nucleotide polymorphism identified with altered response to clozapine

OBJECTIVE: to determine if the agonist serotonin and antagonists loxapine and clozapine have an altered potency for four allelic variants (T25N, I197V, A447V, and H452Y) of the human 5HT2A receptor when compared to the wild-type allele. METHODS: The receptor or its variants are studied in an in-vitro functional assay system consisting of a Sf9 insect cell line that is stably transformed with the human wild-type and mutant alleles. This assay system measures release of calcium stores due to receptor activation by agonists and inhibition of this agonist stimulated response by antagonists. RESULTS: Both loxapine and clozapine exhibit non-competitive antagonism of serotonin stimulation of the human 5HT2A receptor signal transduction system and loxapine is the more potent inhibitor. This study shows that the I197V allele requires a two-fold higher concentration of the atypical neuroleptic clozapine to inhibit serotonin stimulation compared to the wild-type receptor (P = 0.036). The I197V mutation does not affect the inhibition of serotonin stimulation by the typical neuroleptic loxapine nor does it alter the activation of the receptor by serotonin. It is also significant that the results of this study indicate that the T25N, A447V, and H452Y mutations in the human 5HT2A receptor do not significantly alter the response of the receptor to the agonist serotonin or the antagonists loxapine and clozapine.     

Utilizing Internal Standard Responses to Assess Risk on Reporting Bioanalytical Results from Hemolyzed Samples

Bioanalytical analysis of toxicokinetic and pharmacokinetic samples is an integral part of small molecule drugs development and liquid chromatography—tandem mass spectrometry (LC-MS/MS) has been the technique of choice. One important consideration is the matrix effect, in which ionization of the analytes of interest is affected by the presence of co-eluting interfering components present in the sample matrix. Hemolysis, which results in additional endogenous components being released from the lysed red blood cells, may cause additional matrix interferences. The effects of the degree of hemolysis on the accuracy and precision of the method and the reported sample concentrations from hemolyzed study samples have drawn increasing attention in recent years, especially in cases where the sample concentrations are critical for pharmacokinetic calculation. Currently, there is no established procedure to objectively assess the risk of reporting potentially inaccurate bioanalytical results from hemolyzed study samples. In this work, we evaluated the effect of different degrees of hemolysis on the internal standard peak area, accuracy, and precision of the analyses of BMS-906024 and its metabolite, BMS-911557, in human plasma by LC-MS/MS. In addition, we proposed the strategy of using the peak area of the stable isotope-labeled internal standard (SIL-IS) from the LC-MS/MS measurement as the surrogate marker for risk assessment. Samples with peak areas outside of the pre-defined acceptance criteria, e.g., less than 50% or more than 150% of the average IS response in study samples, plasma standards, and QC samples when SIL-IS is used, are flagged out for further investigation.KEY WORDS: hemolyzed sample/haemolyzed sample, hyperlipemic sample, internal standard peak area/internal standard responses, LC-MS/MS, regulated bioanalysis, risk assessment     

Lesions of the dorsal noradrenergic projection attenuate morphine- but not amphetamine-induced conditioned taste aversion

Perlapine is a dibenzohetereopine compound chemically related to clothiapine, loxapine, and clozapine. Although the latter three compounds are antipsychotic, perlapine has not been reported to be antipsychotic. Nevertheless, all four drugs increase rat plasma prolactin levels. The order of potency is loxapine, perlapine, clothiapine, and clozapine. These results suggest that either perlapine should be reexamined for antipsychotic properties or there are hitherto unsuspected discrepancies between the dopamine receptors relevant to antipsychotic activity in man and those that regulate prolactin secretion in the rat.     

Potentiation of LON 954 tremor by typical and atypical neuroleptics — an indication of striatal dopamine antagonism

Tremor produced in laboratory mice by the benzylimidoylurea derivative LON 954 was potentiated in a dose-dependent manner by a variety of typical and atypical neuroleptics. The most effective agents in this respect were those shown by other workers to have a selective action at dopamine receptors, notably the butyrophenones, thioxanthines and fluphenazine. Chlorpromazine and prochlorperazine produced inconsistent effects while clozapine and loxapine respectively delayed and prolonged the peak tremor response. While these findings support primary involvement of striatal dopaminergic mechanisms in LON 954 tremorogenesis, a reduction in cyclic AMP levels may be an important factor in the observed effects.     

Clozapine reversal of the deficits in coordinated movement induced by D2 receptor blockade does not depend upon antagonism of α2 adrenoceptors

Alpha2 adrenoceptor antagonists have been shown to reverse D2-antagonist-induced catalepsy leading to the hypothesis that the alpha2 antagonistic properties of clozapine underlie the compound's lack of extrapyramidal symptoms in the clinic. The potential for alpha2 antagonists to reverse the motor deficits produced by D2 antagonists (loxapine and haloperidol) was further investigated using a rotating rod (3.5 rpm) test in male Sprague-Dawley rats that requires coordinated movement to perform the task. The effects of loxapine (0.3 mg/kg, s.c.) were dose-dependently and statistically significantly reversed by the administration of clozapine (1,3, 10 mg/kg, i.p., n=10). Isoloxapine (1 mg/kg, i.p.), RX 821002 (2-methoxy-idazoxan; 5.6 mg/kg, i.p.) and yohimbine (5.6 mg/kg, i.p.) did not reverse the effects of loxapine. Furthermore, the motor deficits produced by haloperidol could not be reversed by RX 821002 (5.6 mg/kg, i.p.) or yohimbine (5.6 mg/kg, i.p.). On the other hand, scopolamine (0.03-0.3 mg/kg, i.p.) dose-dependently and statistically significantly antagonised the effects of both loxapine and haloperidol. These results indicate that the anticholinergic rather than the alpha2 antagonistic properties of clozapine may mediate the reversal of the motor deficit induced by D2 antagonism in a rotating rod test.