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The worldwide consumption of illicit drugs presents a big problem in terms of health care and prosecution. In the recent years, hundreds of novel psychoactive substances came up and were traded via the Internet, but there is still a big demand for classic illicit drugs such as cocaine, heroin, cannabis and ecstasy. Among these, cocaine particularly is frequently altered not only with excipients, but also with other physiologically active substances. The purpose of this work was to estimate the trend of cocaine purity and abundance of its adulterants in samples seized by Austrian police from 2012 to 2017. A micro-HPLC method for quantification of cocaine and its most common adulterants was developed and validated using gradient elution and UV detection at four wavelengths. 110 cocaine samples were analysed. In all the samples cocaine was present as hydrochloric salt. Caffeine, procaine, levamisole, phenacetin, lidocaine and benzocaine were the most abundant adulterants.

This review gives an overview of chiral separation principles and their application in enantioselective nano/micro high performance liquid chromatography (n/μ-HPLC) using chiral monolith. In particular, developments in silica and polymer chiral monolithic stationary phases are presented. The preparation and applications of chiral monoliths, the basic chiral separation principles and the mechanisms are discussed. Chirality 25:314–323, 2013. © 2013 Wiley Periodicals, Inc.

A highly sensitive and simple method for determining cryptotanshinone (Cry), tanshinone I (Tan I), and tanshinone IIA (Tan IIA) in Salvia miltiorrhiza was developed using micro HPLC with electrochemical detection (µHPLC-ED). The tanshinones were extracted using an ultrasonic method, with methanol as the extractant. The separation was carried out on a C18 (150 mm × 1.0 mm i.d., 3 µm particle size) analytical column. The mobile phase was acetonitrile-water-formic acid mixture (52:48:0.6, v/v/v) solution. The flow rate and the temperature of the column were set at 30 µL/min and 35°C. The applied potential was set at −0.4 V vs. Ag/AgCl. The peak heights for Cry, Tan I, and Tan IIA were found to be linearly related to the amounts injected, ranging from 0.145 µmol/L to 3.88 µmol/L, 0.226 µmol/L to 3.01 µmol/L, and 0.149 µmol/L to 3.98 µmol/L, respectively. The RSD values of intra-day precision and repeatability were not more than 3.0%, and the recovery of three analytes were ranged from 96.7% to 97.5%. The resu...

Micro-high-performance liquid chromatography is a miniaturized, economic and ecological chromatographic system allowing the use of reduced size chromatographic columns. Coupled with electrospray ionization tandem mass spectrometry, this technique can be used to detect and quantify low concentrations of peptides. In this study, hepcidin was used as the model compound and analysed using octadecylsilica stationary phase by means of a gradient elution mode at a flow rate of 4 μL/min. Several parameters were studied to optimize peak focusing. Using the methodology of experimental design, the mobile-phase gradient conditions and the sample composition were optimized in order to maximize the sensitivity and minimize retention time. Stability of the target peptide in solution was also demonstrated.

A simple, fast, sensitive, and environmental friendly micro-method is described for the determination of desmosterol and cholesterol in milk samples using isocratic normal phase high performance liquid chromatography and diode array detection. After sample micro-saponification, the chromatographic separation is achieved in 10 min, further reduced to 6 min when only cholesterol is expected to be present. The method is accurate, presenting cholesterol and desmosterol recoveries >96% and inter-day RSD lower than 3%. Quantification limits were clearly below the requirements for any milk sample, with 40 and 20 μg/100 mL for cholesterol and desmosterol, respectively. Several raw and UHT commercial milk samples, infant powder formulas, and human breast milks were analyzed, with cholesterol and desmosterol (present only in the latter) contents within reported amounts. The proposed method proved to be simple and feasible for determination of a large number of samples, requiring less solvent consumption (9–13 mL of hexane for all saponification/extraction/chromatographic steps) and simpler equipment than most ones reported, and a further possibility of partial solvent recycling due to the isocratic chromatographic mode.

The purpose of this study is to improve the detection limit for trace herbicides, and to separate all samples within a short time with the combination of temperature and flow programming with micro‐reversed‐phase liquid chromatography (RPLC). The optimum condition for separation was ACN:0.05 M NaH2PO4 (46:54) (v/v), pH = 4.3, 40°C. The mass sensitivity is in the range between 0.086 × 10−13 g and 3.34 × 10−13 g in micro‐HPLC (HPLC). Micro‐HPLC exhibits higher mass sensitivity and better heat transfer than conventional HPLC. Thus, in the case of micro‐HPLC, the retention behavior of herbicides is easily determined according to the change of temperature. Especially, retention of triazines is decreased to a lesser extent with the increase of column temperature than that of other herbicides. This tendency has been accounted for the thermodynamic parameters ΔH° and ΔS°. The ΔS° for triazines is less negative than that for phenoxy acids, esters, and others. The chromatograms of herbicides were obtained ...

Objectives: the development of a simple, rapid, sensitive, and accurate HPLC-UV method for the simultaneous determination of retinol and α-tocopherol in human plasma, suitable for the evaluation of these vitamins in pregnant women suffering from intrahepatic cholestasis of pregnancy (ICP). (b) Design and methods: chromatographic separation of vitamins was achieved with a microcolumn BDS HYPERSIL C18 (100 mm × 2.1 mm, 2.4 μm) using a C18 guard column. The developed and validated HPLC method proposed in this study was applied in the assessment of plasma concentrations of retinol and α-tocopherol in normal pregnancy (n = 37) and in pregnancy complicated with ICP (n = 19). (c) Results: the validation of the method showed excellent linearity for retinol and α-tocopherol (r2: 0.998 and 0.997), high sensitivity (LOD: 0.02 and 0.11 μM, LOQ: 0.07 and 0.36 μM), and high recovery (96.0–104.0% and 99.3–102.0%), respectively. The method requires a low sample volume and all procedures of sample preparation and analytical determination take less than 20 min to be completed. The evaluation of the results in ICP patients showed that α-tocopherol significantly diminished compared to normal pregnant women (13.1 ± 2.9 vs. 22.4 ± 2.2 μM, p < 0.05) whereas retinol remains unchanged (1.27 ± 0.21 vs. 1.25 ± 0.10 μM). (d) Conclusions: a simple, accurate, reliable, selective, highly sensitive and cost effective method suitable for routine determination of retinol and α-tocopherol in biological samples is proposed. It was possible to determine the decrease of α-tocopherol in ICP patients by this method. Fil: Martinefski, Manuela Romina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Scioscia, Silvia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina Fil: Contin, Mario Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Samassa, Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; Argentina Fil: Lucangioli, Silvia Edith. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Tripodi, Valeria Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The main difficulty in micro-HPLC separation is the manipulation with the composition of the mobile phase (degassing of solvents and a slow establishment of equilibrium) but the problem of elution can be solved by temperature optimalization. The effect of temperature in micro-HPLC separation of the 16 polycyclic aromatic hydrocarbons (PAHs) (mixture SRM 1647 of the US EPA) has been studied using conventional C18 and new developed AP phase (an amide group localized in the hydrophobic ligands). All the investigations have been performed under isocratic conditions (binary hydroorganic mobile phase: acetonitrile/water). The results have shown that, in the case of AP phase, application of temperature gradient (from 298 to 303 K), enabled the attainment of complete 16 PAHs separation (especially of the first 4 solutes).

A micro high-performance liquid chromatography (HPLC) method has been developed for the determination of the anti-coccidial drug nicarbazin in chicken tissues, eggs, poultry feeds and litter. The 4,4′-dinitrocarbanilide (DNC) component of nicarbazin was extracted from foods, feeds and litter with acetonitrile. The extracts were purified by liquid-liquid partitioning, evaporated to dryness and taken up in methanol-acetonitrile-water (50:30:20, v/v). Micro HPLC of the 4,4′-dinitrocarbanilide (DNC) portion of nicarbazin is performed isocratically using a small bore column (1 mm I.D.) packed with reversed-phase and a UV detector set at 340 nm. The average recoveries of nicarbazin added to muscle, liver and egg were 92.8, 84.3 and 85.2%, respectively, 95.9% in poultry feed and 76.8–95.9% in different litters. The limit of detection was 25 pg, based on a detector signal-to-noise ratio of 3. These results were achieved with a simplified step extraction without the solid-phase extraction used by various researchers. This method offers a sensitive, selective, rapid, and less expensive alternative to conventional HPLC for such evaluations.

The generation of a micro-gradient for micro HPLC capillary columns is described. The system used is a modified and improved version of a split flow gradient elution device. Gradient tests have been performed and have shown good reproducibility under all conditions. The system has been successfully coupled with a particle beam LC-MS interface and the analysis of a mixture of twenty seven basic or neutral pesticides is reported.

The purpose of the study was to develop a micro HPLC system with physically changeable selectivity. This was done using two series-coupled beds of chemically differing stationary phases in a packed fused silica column. The selectivity change, in fine repeatable steps, was possible by the stepwise moving of a tube oven, covering only 50% of this “tandem column”. Each step of selectivity started with a position change of the oven, thus heating up a fresh position of the more polar and the non-polar column bed. As the chromatogram is thus repeated under these new selectivity conditions, multiple chromatograms result. For this reason we call the technique “Multi Micro HPLC”. This very simple mode of operation provides an analytical tool for developing separation conditions and which allows optimizing for a given special sample and checking for one of the most critical problems in HPLC: unidentified peak overlapping. The selectivity changes are nonlinearly correlated with the oven position with regards to temperature field distribution and are greater than is possible by simple change of column temperature. Micropacked columns are ideal for quick temperature changes. Elevated temperatures in HPLC help to shorten analysis time. The concepts discussed above provide an explanation of how a normal, formerly chemically homogeneous, column can become very temperature sensitive after detoriation at the inlet. In fact the column has become an unintentional “tandem column” and peak positions tend to move erratically as its selectivity changes drastically by inhomogeneous temperature changes along the separation path.

Organic-silica hybrid monolithic columns have drawn more and more attention due to the ease of preparation and good mechanical stability in recent years. Many synthetic approaches have been developed and a variety of hybrid monolithic capillary columns have been prepared. The sol-gel process is well recognized in the fabrication of hybrid monolithic columns, which can be mainly classified as one-step, acid/base two-step procedures. The new approaches such as the " one-pot'' and nano-scaled inorganic-organic hybrid reagent of polyhedral oligomeric silsesquioxane used as a cross-linker have also emerged for the preparation of hybrid monolithic columns. The applications of the organic-silica hybrid monolithic capillary columns for capillary electrochromatography, micro high-performance liquid chromatography, solid-phase microextraction and enzymatic reactor etc. are included in this review.

A new sampling procedure for individual raindrops with volumes of 4 nl - 4 μl is presented. It is demonstrated that analyte concentrations in small volumes can be analysed using micro-HPLC and capillary zone electrophoresis (CZE). Results for the analysis of cations such as Na+, NH4 +, K+, Mg2+, Ca2+, and anions such as Cl−, SO4 2-, NO3 −, NO2 − and organic acids are given and discussed.

This article reviews the works published since 2001 (included) on the micro/nano-HPLC analysis of bioactive and biomarker peptides. The main achievements related to the improvement of the detection sensitivity, quantitation repeatability and reproducibility, and separation selectivity are highlighted. A wide attention is paid to the application of micro/nano-HPLC to the analysis of bioactive peptides in biological matrices. The uses of micro/nano-HPLC in peptidomics to discover new endogenous bioactive peptides and to develop quantitation procedures to compare the levels of peptides of interest in two different biological samples are also considered. Finally, the application of micro/nano-HPLC to the analysis of biomarker peptides for various diseases is also included in this review.

A micro high-performance liquid chromatographic (micro-HPLC) procedure for the assay of digitoxin tablets and deslanoside injections has been developed. Micro-HPLC is performed on an ODS micro column, with acetonitrile-methanol-water (10:20:17) for digitoxin tablets and acetonitrile-water (21:70) for deslanoside injections. The effluent is monitored by UV absorption at 220 nm. Quantitation of cardiac glycosides in tablets and injections is carried out by the internal standard method. The composite assay results for digitoxin tablets and deslanoside injections provide average values of 101.2 and 99.9% with standard deviations of 1.2 and 0.93%, respectively. This micro-HPLC method is sensitive, quantitative, and reproducible. It is suitable for use in examining the content uniformity of pharmaceutical preparations.

A highly sensitive determination method for troglitazone stereoisomers was developed by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The oxidation behavior of troglitazone was investigated for the application of ECD by measuring the cyclic voltammogram. The separation was performed on a semi-micro chiral column (Chiralcel OJ-RH) using a mobile phase consisting of methanol-acetic acid (1000:1, v/v) containing 50mM LiClO4 at a flow rate of 20 microl/min. The peak areas of the stereoisomers separated from 0.1 to 50 ng/ml of troglitazone had good linearity with correlation coefficients of >0.999, and had similar response. The limit of detection was 1.3 fmol (signal-to-noise ratio of 3). This method was applied to the determination of troglitazone stereoisomers in rat plasma. The levels of troglitazone stereoisomers in rat plasma could be monitored until 24h after the oral administration.

A dry-packing method has been developed which enables the preparation of packed capillary columns for micro HPLC from 250 μm i.d. tubing and 5 μm packing materials. Pressurized gases, such as hydrogen and argon, were used to transport the packing media, and ethanol or methanol were used as discharge agents. By changing the gas pressure, the packing density could be easily adjusted. It was found that, within experimental limits, the higher the packing density, the greater the column efficiency. Comparison between dry- and slurrypacked columns showed that the former had greatly improved stability; the efficiency of dry-packed columns was about the same as, or even better than, that obtained by slurry-packing.

Thermal lensing (TL) permits ultrasensitive measurements of optical absorption of analytes in very small volumes. Separation-detection conditions of non-labeled amino acids with micro-HPLC/UV absorption detector are optimized, and direct determination of non-labeled amino acids by micro-HPLC/UV-excitation TL detection in a gradient elution is successfully demonstrated. Non-labeled amol-level amino acids is detectable with the TL detection system, which has thousand times better sensitivity than a conventional UV detector.

Plastic tubing of polyetheretherketone (PEEK) is used for the preparation of HPLC packed capillary columns. The polymer is rigid but not fragile, has great resistance to chemical and physical agents and comes in standard 1/16″ O.D. These features can extend the column lifetime and facilitate the overall employment of HPLC capillary columns. Serial connection of short columns is also possible with no increase in dead volume. A new, rapid and effective packing method has been developed to be compatible with the characteristics of the material. Several C8 and C18 columns have been prepared and tested and some applications are shown.

A new method is introduced for packing micro-columns with an ID (inner diameter) of 320 μm. The advantage of this method is the extraordinary economy of the packing material employed and the high reliability in production. The theoretical plate height ranges from 7 to 8 μm for 3 μm particles.

The retention and selectivity behaviour of some antiepileptic drugs were studied by micro high-performance liquid chromatography on nine types of phenyl-modified glasses, prepared with xylene solution containing phenyldimethylchlorosilane (P), diphenylmethylchlorosilane (D) or triphenylchlorosilane (T), using three types of glass with various mean pore diameters and/or specific surface areas. From elemental analysis data for carbon, the maximum number of accessible phenyl surface groups per 100A2 of glass (mean pore diameter: 335A, specific surface area: 69m2/g) in P, D and T gel was calculated to be 2.38, 1.58 and 0.76, respectively. Using various CH3CN−0.01 M KH2PO4 mixtures as eluents, the antiepileptic drugs were separated on all the glasses studied, but with different degrees of resolution. With an increase in the specific surface area, the k′ values of some antiepileptic drugs also increased.

Recherche des parametres optimisants, qui sont nombreux: type de pompe, melange initial, nature des solvants, debits, geometrie de la cellule de melange, etc...

Microcolumn techniques involving pre-column concentration and post-column derivatization make good use of micro-scale high-performance liquid chromatography. The efficient use of microcolumns is illustrated by some applications to the analysis of amino acids, bile acids and catecholamines. The potential of new detector techniques based on the multichannel photodiode array detector, and on immobilized enzyme post-column reaction systems with fluorimetric detection, is also discussed.

Infrared monitoring was accomplished in reversed phase HPLC on using deuterated solvents. The end of a micro HPLC column was flattend and used as a flow cell for on-column IR detection. Detection of alkylbenzenes and oil-soluble vitamins which were separeted on ODS packing with CD3CN/D2O and CD3OD, respectively, was performed at 2940 cm−1.

低級脂肪族アミン及び置換フェノール類を塩化4-ジメチルアミノアゾベンゼン-4'-スルホニル(Dabsyl-Cl)と反応させ,又脂肪族アルデヒドはダブシルヒドラジンと反応させダブシルヒドラゾンとして共鳴ラマン効果が期待できる誘導体に変換した.これらの誘導体は逆相セミミクロカラム(μS-Finepak C18,1.5mmφ×250mm)で分離後,その溶離成分をアルゴンイオンレーザー488.0nmの発振波長を用いて1136cm-1で共鳴ラマン検出を行った.レーザー出力,スリット幅,スムージング数など検出感度に影響を与える要因の検討を行い,ラマン検出の最適条件を調べた.その結果,従来の内径4,6mmのカラムを使用したLC/ラマン検出と比べて検出限界は絶対注入量で20倍向上し,2ngまで検出可能であった.

長鎖脂肪族カルボン酸の誘導体化試薬として,Arイオンレーザーの励起光に近接した波長領域に吸収を示す4-ニトロ-4'-N・メチル,N・β-ヒドロキシエチルアミノアゾベンゼンを合成した.カルボン酸は二塩化オキサリルで酸クロライドとした後,誘導体化試薬を用いてエステル誘導体とした.これらの誘導体は逆相セミ・ミクロカラムで分離後,その溶離成分を1343cm-1のラマンバンドに設定して共鳴ラマン検出した.その結果,ラウリン酸では5～200ppmの濃度範囲で検量線は直線を示した.20 ppmでの相対標準偏差(n=5)は4.4%と良好であった.

Detecteurs optiques, a barette de diodes, laser, electrochimiques, du type CG, a induction de plasma

The advantages of short microbore columns packed with a sorbent having a particle diameter of 3µm, such as the speed of analysis, the high solute concentration in the effluent and the detectability of small quantities are experimentally verified. The broadening in the valve is eliminated by the peak compression technique reached by adding a ion-pairing agent into the sample. The examples of catecholamines show the dependence of the height equivalent to a theoretical plate on the velocity of the mobile phase. The optimum is h=3 for a column 30mm long, i.d. 0.7mm, particle diameter 3µm. The minimal detectable quantity with a two-electrode amperometric detector with a gold electrode is from 30 to 40fmol for catecholamines.

The chromatographic performance of deuterated solvents, heavy water and deuteriobenzene, has been investigated in reversed phase and normal phase micro-HPLC. The performance of heavy water in separation was comparable or superior to that of light water in reversed phase mode. A slight improvement was also observed in catecholamines separation with heavy water. The performance of deuteriobenzene was observed as complicated in metal complexes separation, but a little difference was present. From those results, the combinations of micro HPLC and IR via flow-cell technique, proton-NMR, and ICP could be accomplished free from absorption or signals from mobile phase solvents.

High-performance micro packed fused-silica and open-tubular glass capillary columns were prepared and applied to separations of complex mixtures. Solvent-gradient elution proved quite useful for the separation of solutes with wide polarity. Instruments and some applications are described.

The capcity factors determined by reversed-phase micro high performance liquid chromatography (micro-HPLC) can be used as one of the descriptors in Quantitative-Structure-Activity-Relationships (QSAR) studies. The present method gives a more simple and convenient way to study relationships between physicochemical properties and biological activities of some drugs.

A miniaturized continuous gradient elution system with variable gradient profile was designed. A retention time reproducibility below 1% was achieved. The system was applied to the separation of phenolic compounds with a wide range of polarities.

The combination technique of micro high performance liquid chromatography and inductively coupled plasma atomic emission spectrometry is demonstrated in the separation of organometallic compounds. Problems relating to the interfacing between micro HPLC and ICP would be elininated uti1izing the simple interfacing technique.

Application de la methode du titre a l'analyse des hydrocarbures paraffiniques et aromatiques d'une fraction essence

The interface for direct coupling of micro HPLC with FAB mass spectrometry has been evaluated as a simple sample introduction system using unstable and/or non-volatile compounds having higher molecular weight. The good reproducibility of chromatograms, little fluctuation and small tailing in chromatographic peak profiles, and the excellent quality of mass spectral patterns were obtained. High-molecular-weight compounds such as parathyroid hormone and insulin chain B could be introduced and ionized stably with high sensitivity.

The exclusion properties of ten commercially available silica gels have been determined and their relative merits for use as stationary phases in exclusion chromatography discussed. Examples are given of the use of three selected silica gels in the separation of synthetic mixtures of high-molecular-weight standards. The effect of the exclusion properties of silica gel on retention data is considered and a modified retention volume equation that takes into account these exclusion properties is given. The validity of the equation is tested against retention data determined for three different solutes chromatographed on three silica gels of widely different porosities. The use of silica gel as an exclusion medium in conjunction with a column having 250,000 theoretical plates is also demonstrated.

The chromatographic potential of very short fused-silica column (30 mm length) packed with 3-μm particles has been investigated. The results indicate that this kind of micro-column has high applicability for a rapid identification of several samples. This technique also meets the recent demands in HPLC, as low solvent consumption and faster analysis time.

The application of micro HPLC to the determination of amygdalin in Semen pruni armeniacae and Semen pruni persicae is described. Amygdalin is separated at ambient temperature on a reversed phase column of U-Finepak SIL C18(150 x 0.5 mm) with methanol + water (25:75 v/v) as the mobile phase at a flow rate of 10 microL/min. The results are calculated by the internal standard method. The linear range is 1-7 micrograms. The CV and recovery of pure amygdalin are 1.47% (n = 10) and 98.13%, respectively. The results of analysis are lower than those obtained by TLC, but microHPLC is much simpler, faster, and more sensitive and reproducible than TLC.

Utilization of micro-HPLC is described for the direct measurement of the partition coefficients needed in studying the quantitative structure — activity relationships (QSAR). The method involves analyzing the solutes in acetonitrile — water as the mobile phase on commercially available reversed-phase stationary phases.

Publisher Summary This chapter discusses the combination of micro-HPLC and IR spectroscopy. High-performance liquid chromatography (HPLC) has become an extremely powerful technique for separating mixtures into their constituents , with the recent developments in the packing materials and pumps. HPLC permits separations of a wide variety of mixtures containing non-volatile or temperature-sensitive compounds which cannot be separated readily by gas chromatography (GC). However, no universal equivalent in HPLC to thermal conductivity or flame ionization detection in GC is available, because various mobile phases are used and the physical properties of both the mobile phase and the sample components are often quite similar. Although there are two detection methods based on UV absorption and refractive index, which are the most frequently used, they provide little structural information on the separated species. Infrared spectrometry ( I R ) is undoubtedly one of the most useful tools providing qualitative information.

The importance of dispersion in High Performance Liquid Chromatography (HPLC) is emphasised. The state of the art of Micro HPLC techniques such as high speed HPLC and narrow bore HPLC are reviewed.

Various types of open-tubular capillary columns are prepared and employed as separation tools in liquid chromatography(LC). Preparation procedures and the apparatus for open-tubular capillary LC are described and the performance of capillary columns is discussed.

The possibility of high-speed micro-HPLC has been investigated using a short micro-column (35 mm × 0.5 mm i.d.) packed with 3 μm ODS particle. The results indicate that this approach has considerable potential for good separations with short analysis time. A typical example shows only three minutes is required with a plate count of 3,800 to separate seven PAHs.

The separation of polycyclic aromatic hydrocarbons (PAH) on various reversed-phase columns (phenyl, ethyl, octyl and octadecyl) have been compared. The correlations between the logarithm of capacity factor (log k′) and several descriptors, which show the molecular size, shape and physical property of a solute, were determined. The results indicated the high possibility to predict the retention of PAH in reversed-phase high performance liquid chromatography.