Hiroyuki Kataoka

• PhD
• Professor (Full) at Shujitsu University

Despite advancements in the sensitivity and performance of analytical instruments, sample preparation remains a bottleneck in the analytical process. Currently, solid-phase extraction is more widely used than traditional organic solvent extraction due to its ease of use and lower solvent requirements. Moreover, various microextraction techniques su...

Passive smoking from environmental tobacco smoke not only increases the risk of lung cancer and cardiovascular disease but may also be a stressor triggering neuropsychiatric and other disorders. To prevent these diseases, understanding the relationship between passive smoking and stress is vital. In this study, we developed a simple and sensitive m...

Herbal teas have attracted attention as functional beverages containing luteolin and apigenin, which exhibit antioxidant and anti-inflammatory effects. The objective of this study was to develop a sensitive online automated method to determine these flavones’ contents in herbal teas using in-tube solid-phase microextraction (IT-SPME) coupled with l...

Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liqu...

Abstract: Column-switching techniques, employing two or more stationary-phase columns, multi-port valves, and one or more pumps, play a crucial role in trace enrichment and automated online sample cleanup for analytes within complex matrices. They are typically used in conjunction with high-performance liquid chromatography. Convenient column-switc...

Contamination of active pharmaceutical ingredients (APIs) and pharmaceutical preparations with carcinogenic N-nitrosamines has led to recalls of these products and supply shortages to patients. The present study describes the development of a highly sensitive method for simultaneous analysis of seven N-nitrosamines using on-line in-tube solid-phase...

Solid Phase Microextraction (SPME) is a flexible and convenient sampling and sample preparation technique that extracts different kinds of analytes, including both volatile and non-volatile, without the use of a solvent. The technique facilitates fast, simple and automated determination of target analytes in a range of matrices. As it offers a gree...

Living organisms, such as microorganisms, plants and animals, are composed of complex constituents, which may include bioactive components that maintain their functions [...]

To objectively and quantitatively assess the degree of stress, we developed a simple and sensitive method for the simultaneous determination of four steroidal stress biomarkers in saliva: cortisol (CRT), testosterone (TES), dehydroepiandrosterone (DHEA) and DHEA sulfate (DHAES), by on-line coupling of automated in-tube solid-phase microextraction (...

Accurate measurement of sulfated steroid metabolite concentrations can not only enable the elucidation of the mechanisms regulating steroid metabolism, but also lead to the diagnosis of various related diseases. The present study describes a simple and sensitive method for the simultaneous determination of four sulfated steroid metabolites in saliv...

Passive smoking due to environmental tobacco smoke is a serious public health concern because it increases the risk of lung cancer and cardiovascular disease. However, the current status and effect of passive smoking in various lifestyles are not fully understood. In this study, we measured hair nicotine and cotinine levels as exposure biomarkers i...

The differentiation of a controlled drug from uncontrolled novel compounds related to regioisomers is a significant issue in forensics. The compound 1-(2,3-dihydro-1H-inden-5-yl)-2-(pyrrolidin-1-yl)butan-1-one (5-PPDI) is a novel synthetic cathinone first identified in 2015 as a new psychoactive substance. 5-PPDI is the indanyl analog of α-PBP, a t...

The odors and emanations released from the human body can provide important information about the health status of individuals and the presence or absence of diseases. Since these components often emanate from the body surface in very small quantities, a simple sampling and sensitive analytical method is required. In this study, we developed a non-...

Active and passive smoking are serious public health concerns Assessment of tobacco smoke exposure using effective biomarkers is needed. In this study, we developed a simultaneous determination method of five tobacco-specific nitrosamines (TSNAs) in hair by online in-tube solid-phase microextraction (SPME) coupled to liquid chromatography-tandem ma...

In-tube solid-phase microextraction (IT-SPME) was developed about 24 years ago as an effective sample preparation technique using an open tubular capillary column as an extraction device. IT-SPME is useful for micro-concentration, automated sample cleanup, and rapid online analysis, and can be used to determine the analytes in complex matrices simp...

A simple and sensitive method, using automated online in-tube solid-phase microextraction (SPME)coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), was developed for the determination of four tobacco-specific nitrosamines (TSNAs)in mainstream and sidestream smoke of combustion cigarettes and heated tobacco products. These TSNAs...

This study described an automated on‐line method for the simultaneous determination of 8‐isoprostane, 8‐hydroxy‐2′‐deoxyguanosine, and 3‐nitro‐l‐tyrosine in human urine. The method involves in‐tube solid‐phase microextraction using a Carboxen 1006 PLOT capillary column as an extraction device, followed by liquid chromatography with tandem mass spec...

Smoking not only increases the risk of lung cancer but is strongly related to the onset of cardiovascular disease. Particularly, passive smoking due to sidestream smoke is a critical public health problem. To assess active and passive exposure to tobacco smoke, we developed a simple and sensitive method, consisting of on-line in-tube solid phase mi...

Analyses of complex mixtures involve several steps, from sampling to data analysis, any of which can ultimately affect analytical outcomes. Sampling and sample preparation are very important in formulating practical and reliable methods for pharmaceutical analysis. Sampling and sample preparation can be classified into five groups of operation—samp...

Among various analytical processes from sampling to data analysis, sample preparation is the most important step in the extraction, isolation, and concentration of desired analytes in complex matrices, and greatly influences a reliable and accurate analysis. Recent trends in sample preparation include miniaturization, automation, high-throughput pe...

A simple, rapid, and sensitive method was developed for the determination of melatonin (MLT) in human saliva by automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry. MLT was separated within 3 min by high performance liquid chromatography using an Inertsil ODS-3 column and water/ace...

In pharmaceutical and biomedical analyses, sample preparation is essential for the isolation and concentration of target compounds from complex biological matrices. This process is both labor-intensive and error-prone and markedly influences the reliability and accuracy of determining molecules of interest. Solid-phase microextraction (SPME) is a s...

The simultaneous sampling of total suspended particles was performed at 14 sites in Japan during July 2008–June 2009. The spatial correlativity of each particulate composition toward Osaka was obtained for nine selected sites to overview the chemical composition and geographical distribution of particulate components across a wide range of areas na...

Biomedical analyses of drugs and their metabolites are important in new drug development, therapeutic drug monitoring and forensic toxicology. In these analyses, sample preparation is very important to isolate target compounds from complex biological matrices and markedly influences the reliability and accuracy of determination. SPME is a simple an...

A simple and sensitive method for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage in human urine, was developed using automated on-line in-tube solid-phase microextraction (SPME) coupled with stable isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Creatinine was also analyzed si...

A simple and sensitive method for the analysis of oxytocin was developed using automated on-line in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC–MS/MS). Oxytocin was separated within 3 min on a Zorbax Eclipse XDB-C8 column, with water/methanol (10/90, v/v) as the mobile phase at a flow rate...

We have developed a simple and sensitive method for the determination of the oxidative stress biomarker 8-isoprostane (8-IP) in human urine by automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a Zorbax Eclipse XDB-8 column and 0.1% formic acid/methanol (25/75, v/...

Biomedical analyses of chemical agents and their metabolites are important in the development of new drugs, in therapeutic drug monitoring, and in forensic toxicology. In these analyses, sample preparation is essential for the isolation of desired components from complex biological matrices and greatly influences their reliable and accurate determi...

Heterocyclic amines (HCAs) formed in cooked meats and fish are mutagens and carcinogens in rodents and nonprimates. Exposure to HCAs may also be a risk factor for human tumors, but the association between dietary intake and human cancer risk has not been determined. To assess recent exposure to HCAs, we developed a simple and sensitive method for m...

Early disease diagnosis is crucial for human healthcare and successful therapy. Since any changes in homeostatic balance can alter human emanations, the components of breath exhalations and skin emissions may be diagnostic biomarkers for various diseases and metabolic disorders. Since hundreds of endogenous and exogenous volatile organic compounds...

Polycyclic aromatic hydrocarbons (PAHs) are a group of about 10,000 different compounds containing two or more fused aromatic rings made of carbon and hydrogen atoms. Some PAHs are highly carcinogenic and/or genotoxic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. PAHs are ubiquitous environmental pollu...

Column-switching techniques, using two or more stationary-phase columns, are useful for trace enrichment and online automated sample cleanup. Target fractions from the first column are transferred online to a second column having different properties for further separation by zone cutting and flushing techniques. Column-switching techniques can be...

We have developed a simple and sensitive method for the simultaneous determination of stress-related hormones such as cortisol (CRT) and dehydroepiandrosterone (DHEA) in saliva by automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). CRT and DHEA were separated within 5 m...

We have developed a simple and sensitive method for the simultaneous determination of testosterone (TES), cortisol (CRT), and dehydroepiandrosterone (DHEA) in saliva by automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a Discovery HS F5 column. The optimum in-tub...

Aflatoxin B1 (AFB1) is a potent mycotoxin that induces hepatocellular carcinoma in many animal species, including humans. In this study, we examined the effects of AFB1 on UDP-glucuronosyltransferase (UGT) mRNA expression in HepG2 cells (human hepatocellular carcinoma cell line). The cells were treated with AFB1 for 48 h at a concentration of 10 μM...

We have developed a simple and sensitive method for the simultaneous determination of the antiviral drug oseltamivir (OS) and its metabolite oseltamivir carboxylate (OSC) in environmental waters by automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). OS and OSC were sepa...

Column switching techniques, using two or more stationary phase columns, are useful for trace enrichment and online automated sample preparation. Target fractions from the first column are transferred online to a second column with different properties for further separation. Column switching techniques can be used to determine the analytes in a co...

Although mutagenic and carcinogenic heterocyclic amines (HCAs) are known to be formed in cooked meat and fish, human HCA exposure and carcinogenic risk have not been elucidated in sufficient detail. In this work, we investigated the formations of HCA–amino acid adducts in a model system by using a liquid chromatography–mass spectrometry to elucidat...

A simple and sensitive method for the determination of ochratoxins A and B in nuts and grain samples was developed using an automated in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Ochratoxins were separated within 5 min by high-performance liquid chromatography using an Inertsil ODS-3 colum...

Perfluorooctane sulfonate (PFOS) is a chemically stable compound extensively used as oil and water repellent, surface active agents in our daily life. Accumulative research evidence gradually appears the toxicity of PFOS against mammals, but the whole figure remains to be elucidated. The present study was conducted to know the effects of PFOS on hu...

Sample preparation is important for the isolation and concentration of desired trace components from complex matrices. Sample preparation is the most labor-intensive and error-prone process in analytical methodology, and greatly influences the reliable and accurate determination of analytes. The integration of sample preparation with various analyt...

Biomedical analyses of drugs, metabolites, poisons, environmental and occupational pollutants, disease biomarkers and endogenous substances in body fluids and tissues are important in the development of new drugs, therapeutic monitoring, forensic toxicology, patient diagnosis, and biomonitoring of human exposure to hazardous chemicals. In these ana...

Tea products and crude drugs were analyzed to determine levels of contamination with 15 polycyclic aromatic hydrocarbons (PAHs) using a new online automated method, consisting of in-tube solid-phase microextraction (SPME) coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). PAHs were separated within 15 min by HPLC...

Natural products have served as major sources of drugs for centuries, and about half of the pharmaceuticals in use today are derived from natural products. Therefore, screening and analysis of the bioactive components in medicinal plants are now indispensable for the discovery of new drugs and quality control of plant pharmaceuticals. Sample prepar...

About half of the are pharmaceuticals in use today are derived from natural products, including from herbal medicines. Quality control is of particular importance, with detection and analysis of contaminants being indispensable. Sample preparation is essential for isolating desired compounds from complex matrices. We describe here a new sample prep...

A simple and sensitive automated method, consisting of in-tube solid-phase microextraction (SPME) coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD), was developed for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) in food samples. PAHs were separated within 15 min by HPLC using a Zorbax Eclipse P...

A simple, rapid and sensitive method was developed for determining the presence of seven anabolic steroids (boldenone, nandrolone, testosterone, methyltestosterone, epiandrosterone, androsterone, and atnozolol) in human urine. Glucuronide-conjugates of these compounds were hydrolyzed with beta-glucuronidase. The anabolic steroids were analyzed by o...

Heterocyclic amine (HCA) concentrations were measured in meat and fish samples cooked by pan-frying, grilling and churrasco (Brazilian barbecue) to various levels of doneness in accordance with the cooking methods most commonly used in Brazil. HCAs were extracted by the Blue-rayon absorption method and measured by liquid chromatography-mass spectro...

We have developed a simple, rapid, and sensitive method for the determination of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) by on-line in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). PFOA and PFOS were separated within 10 min by high-performance liquid chromatography u...

Sample preparation is important for isolating desired components from complex matrices and greatly influences their reliable and accurate analysis. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, and reduction in solvent consumption and operation time. This review focuses on novel microextractio...

Sample preparation is important for isolating desired components from complex matrices and greatly influences their reliable and accurate analysis. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, online coupling with analytical instruments, and low-cost operation through extremely low or no solv...

Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds found in cooked meat and fish. Although HCAs are known to form adducts with protein after metabolic activation, adduct formation during cooking has not been elucidated. In this study, we showed that 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is released from high molecu...

A simple and sensitive method for the determination of patulin in fruit juice and dried fruit samples was developed using a fully automated method consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Patulin was separated within 5 min by high-performance liquid chromatography using a...

A simple and sensitive automated method for determination of aflatoxins (B1, B2, G1, and G2) in nuts, cereals, dried fruits, and spices was developed consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography–mass spectrometry (LC–MS). Aflatoxins were separated within 8 min by high-performance liquid chromatography...

A simple, rapid and sensitive method for the determination of nicotine, cotinine, nornicotine, anabasine, and anatabine in human urine and saliva was developed. These compounds were analyzed by on-line in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Nicotine, cotinine and related alkaloids we...

A simple and sensitive method for the determination of musty odorants, 2-methylisoborneol (MIB) and geosmin (GSM), in environmental water was developed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry. MIB and GSM were separated within 10 min using a DB-1 capillary column and detected in the selec...

A simple and sensitive method for the simultaneous determination of 15 non-steroidal anti-inflammatory drugs (NSAIDs)—acetaminophen, ibuprofen, naproxen, fenoprofen, flurbiprofen, loxoprofen, ketoprofen, mefenamic acid, flufenamic acid, diclofenac, tolfenamic acid, oxaprozin, phenylbutazone, indomethacin, and acemetacin—in environmental water was d...

A simple and sensitive method for the determination of isophorone in food samples was developed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Isophorone was separated within 10 min by GC-MS using a DB-1 capillary column and detected with selective ion monitoring mode. The HS-SPME using...

We developed a simple, rapid, and sensitive method for determination of cortisol levels in human saliva. Cortisol was analyzed by on-line in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC/MS). Cortisol was separated within 5 min by HPLC using an Eclipse ZDB-C8 column and 1% acetic acid/methanol (50/...

This study aimed to test the possible use of unmetabolized volatile organic compounds (VOCs) in urine as biomarkers of low-level indoor environmental exposure. Twenty-four subjects in 13 dwellings in a prefecture of Japan participated in this study. Air samples of the breathing zone were collected in the living room and bedroom, along with spot uri...

A simple and sensitive method for the determination of abietic acid and dehydroabietic acid in food samples was developed using a fully automated method consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC/MS). These compounds were separated within 5min by HPLC using an ODS-3 column and 5...

A selective and sensitive method for the analysis of aromatic amines by GC was developed. Aromatic amines were converted to their N-n-propoxycarbonyl derivatives and measured by GC with nitrogen-phosphorus selective detection (NPD) using an HP-5 fused-silica capillary column. The derivatives of the 20 aromatic amines provided excellent NPD response...

Mutagenic/carcinogenic 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole [aminophenylnorharman (APNH)] is formed from norharman and aniline in the presence of cytochrome P450 3A4/1A2. Because both precursors are widely distributed in the environment, human exposure is unavoidable. To clarify APNH formation in the human body, amounts of the compound in 24-h...

A selective and sensitive method for the analysis of aromatic amines by GC was developed. Aromatic amines were converted to their N-n-propoxycarbonyl derivatives and measured by GC with nitrogen-phosphorus selective detection (NPD) using an HP-5 fused-silica capillary column. The derivatives of the 20 aromatic amines provided excellent NPD response...

The presence, identity and quantity of amines in the environment should be established to evaluate possible health hazards. In many cases, environmental amines are present at very low concentration and are often found among a myriad of other compounds from which they must be separated and identified. Therefore, analytical methodology for the isolat...

A sensitive and precise method for the simultaneous determination of hippuric acid, o-, m- and p-methylhippuric acids, mandelic acid and phenylglyoxylic acid, which are major urinary metabolites of toluene, o-, m- and p-xylenes, styrene and ethylbenzene, respectively, was developed. These metabolites were converted into their methyl ester derivativ...

We developed a sensitive and useful method for the determination of five fluoroquinolones (FQs), enoxacin, ofloxacin, ciprofloxacin, norfloxacin, and lomefloxacin in environmental waters, using a fully automated method consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography–tandem mass spectrometry (LC/MS/MS). Th...

The method for the determination of multiclass pesticides in water samples by headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) is described. Of the 174 pesticides, 158 are extracted with a polyacrylate-coated fiber at 30 to 100°C and are classified into four groups according to the shape of their extrac...

We have developed a method using in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry (SPME-LC-MS) for the assay of herbicides in water samples. Chlorinated phenoxy acid herbicides have been automatically extracted into a DB-WAX capillary by repeated draw/eject cycles of sample solution and desorbed with acetonit...

In this chapter, a wide variety of derivatization reactions used for the GC analysis of amines has been surveyed. Some potential problems with derivatization procedures include the formation of unwanted derivatives, the presence of unchanged derivatization reagents, and the requirement for non-aqueous reaction conditions. Amines in environmental an...

No abstract available.

A simple, rapid and sensitive method for the determination of five estrogens, estrone, 17beta-estradiol, estriol, ethynyl estradiol, and diethylstilbestrol, was developed using a fully automated method consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC/MS/MS). These estrogens wer...

Book’s topic The discovery and development of safe and effective new medicines is a long and complex process. Pharmaceutical companies typically invest 9–15 years of research and hundreds of millions of dollars in this effort. With the development of combinatorial chemistry and high-throughput pharmacological testing, the number of new drug candida...

Sample preparation is essential for isolating desired components from complex matrices and greatly influences their reliable and accurate analysis. Solid-phase microextraction (SPME) is a new and effective sample preparation technique. Fibers and capillary tubes coated with an appropriate stationary phase are usually used for SPME, but alternative...

Contamination of infusion solutions with phthalates was analyzed, and its origin was determined. Phthalates were determined by on-line in-tube solid-phase microextraction coupled with high-performance liquid chromatography (in-tube SPME-HPLC) with UV detection. In-tube SPME is an extraction technique for organic compounds in aqueous samples, in whi...

This study demonstrated possible relationships between environmental, personal, and occupational factors and changes in the subjective health symptoms of 214 employees after the relocation of a hospital in a region of Japan. Eight indoor volatile organic compounds (VOCs) were detected in at least one of the 19 rooms investigated, and total VOC (TVO...

A simple and rapid method was developed for analyzing contamination of endocrine disruptors in liquid medicines and intravenous injection solutions. Endocrine disrupting compounds such as bisphenol A (BPA), alkylphenols and phthalates were quantitated by on-line in-tube solid-phase microextraction coupled with high performance liquid chromatography...

Sample preparation is necessary to isolate the desired components from complex matrices, because most analytical instruments cannot handle the matrix directly. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, on-line coupling with analytical instruments and reduction in solvent volume and time. T...

An automated on-line method for the determination of the isoflavones, daidzein and genistein, was developed using in-tube solid-phase microextraction coupled to high-performance liquid chromatography (in-tube SPME-HPLC). In-tube SPME is a new extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sam...

Drug analysis in biological samples and pharmaceutical products is very important for therapeutic drug monitoring (TDM), pharmacokinetic studies, and screening of illicit drugs and development of new medicines. Various biological specimens, particularly plasma, serum, and urine have been used as samples for analysis. The use of milk, tissues, faces...

A cDNA was cloned from Japanese monkey liver mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR) using oligonucleotide primers based on the marmoset cytochrome P450 2D19 (CYP2D19) nucleotide sequence. The full-length cDNA encoded a 497 amino acid protein (designated CYP2D29) that is 96, 91, and 88% homologous to human CYP2D6, cynomolgu...

Norharman is not mutagenic to Salmonella strains, but becomes so to S. typhimurium TA98 and YG1024 with S9 mix in the presence of the non-mutagenic aromatic amine, aniline. The mutagenicity from norharman and aniline in the presence of S9 mix is reported to be due to formation of a mutagenic compound, 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole (amin...

Heterocyclic amines (HCAs) are known mutagens and animal carcinogens formed in cooked meat and fish. Japanese people generally consume more fish than animal meat, and chopped and stir-fried method of meat preparation is favored as much as the grilled cooking method. Therefore, it is supposed that the foods contributing to HCA intake in Japan are di...

A new HPLC method was developed using a chiral column to efficiently separate four 1"-hydroxybufuralol (1"-OH-BF) diastereomers that are major metabolites of bufuralol (BF). Employing this method, we examined diastereomer selectivity in the formation of 1"-OH-BF from BF racemate or enantiomers in four individual samples of human liver microsomes. T...

Sample preparation, such as extraction, concentration, and isolation of analytes, greatly influences their reliable and accurate analysis. In-tube solid-phase microextraction (SPME) is a new effective sample preparation technique using an open tubular fused-silica capillary column as an extraction device. Organic compounds in aqueous samples are di...

An automated on-line method for the analysis of endocrine disruptors related to plastics was developed using in-tube solid-phase microextraction coupled with high performance liquid chromatography (in-tube SPME/HPLC). In-tube SPME is an extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sample di...

In general, analytical methods need various processes such as sampling, sample preparation, separation, detection and data analysis. Over 80% of analysis time is spent on the sampling and sample preparation steps such as extraction, concentration, fractionation and isolation of analytes. Therefore, it is not an exaggeration to say that choice of an...

Aliphatic and aromatic mono-, di- and polyamines are naturally occurring compounds formed as metabolic products in microorganisms, plants, and animals in which the principal routes of amine formation include the decarboxylation of amino acids, amination of carbonyl compounds, and degradation of nitrogen-containing compounds. Amines are also widely...

A single amino acid-substituted mutant protein, CYP2D6 (G42R) was expressed in Saccharomyces cerevisiae and its enzymatic properties were compared with those of other single (P34S, R296C and S486T) and double amino acid-substituted mutant proteins (P34S/S486T and R296C/S486T) expressed in yeast cells, all of which were known to occur in the CYP2D6...