Short-chain Aliphatic Amines Research Articles

Lecithin Microemulsions as Drug Carriers

The paper describes examples of microemulsions based on a well-known biocompatible surfactant, lecithin, and the possibilities of their use as drug carriers. The main problem encountered when developing lecithin microemulsions is the search for suitable cosurfactants. Molecules with short alkyl chains (4–5 C atoms) and relatively large polar “head,” such as short-chain aliphatic alcohols, acids, and amines are most suitable as cosurfactants for the preparation of lecithin microemulsions. Therewith, high concentrations of the cosurfactants (the cosurfactant : lecithin weight ratio usually is 1 : 1) are necessary. Most often, ethanol, n-propanol, or n-butanol are used as cosurfactants for the preparation of lecithin microemulsions in various natural and synthetic oils. To replace toxic alcohols with less toxic components, other well-known surfactants may be added to lecithin microemulsions. They are, e.g., Brij 96V (poly(ethylene glycol) oleate), Tween 80 (polyoxyethylene-20-sorbitan monooleate), Tween 20 (polyoxyethylene-20-sorbitan monolaurate). Triton X-100 (tert-octylphenyl ether of poly(ethylene glycol)) or oleic acid. Composites based on lecithin microemulsions have been described as means for local anesthesia and delivery of vitamins, as well as agents with anti-inflammatory, antifungal, anticancer, and wound healing effects. The considered examples show the promise of the study and development of lecithin microemulsions as drug carriers.

Review of the effect of polyamines in microalgae when ingested by shellfish

Polyamines are a series of short-chain aliphatic amines which can be produced during the metabolism of cells, and are widely distributed in aquatic organisms. Polyamines are important regulators for physiological metabolism, which also eliminate active oxygen free radicals, maintain the normal physiological activities of living organisms, and improve plants' resistance to adverse stresses. However, the knowledge of functional characteristics of polyamines in algae, and their effects on the feeding habits of aquatic organisms, are still limited. In this review, the distribution and characteristics of polyamines in unicellular algae are evaluated. Different characteristics of polyamines in various types of algae, and the effects of polyamines being ingested by shellfish, are critically reviewed and analyzed. So far, most literature references offer the opinion that the partial functions of polyamines are similar to plant hormones. Some microalgae diets have different effects on bivalve mollusks, which could be partly due to characteristic changes of polyamines in algae cells, and their adaptability to external environmental pressure. The goal of this review is to discuss possible reasons why microalgae may be suitable for shellfish feeding. This may provide a new application for microalgae development, as a nutritional feed for shellfish.

Nitrogen-doped graphene oxide monoliths crosslinked by short chain aliphatic amines

Nitrogen-doped graphene oxide monoliths (NGOMs) were readily fabricated by crosslinking graphene oxide (GO) using four different short chain aliphatic amines, i.e., ethylenediamine (EDA), dimethylaminopropylamine (DMPDA), N-isopropylethylenediamine (IPEDA), and triethylenetetramine (TETA). Depending on the structure of the amine crosslinkers, the generated monoliths showed various morphologies with different d spacing, layer thickness, and microspore size. Fourier transform-infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses provided evidence for the formation of covalent CN or CN bonds in all cases, indicating that the interaction of GO with amine crosslinkers involved the ring-opening reaction between GO epoxides and amine groups. The formation of both quaternary nitrogen and some nitrogen-containing heterocyclic composition inside the graphene oxide sheet were also suggested. X-Ray Diffraction (XRD) results indicated that the interspatial distance between GO sheets was increased after crosslinking. The fabricated NGOM-TETA demonstrates potential application as an adsorbent material due to its efficient removal of copper ions.

Simultaneous determination of eight short-chain aliphatic amines in drug substances by HPLC with diode array detection after derivatization with halonitrobenzenes.

Short-chain aliphatic amines are a class of hazardous impurities in drug substances. A simple method, involving derivatization followed by high-performance liquid chromatography with diode array detection, has been developed for residue determination of eight aliphatic amines simultaneously in drug substances. Different halonitrobenzenes derivatization reagents were systematically compared. As a result, 1-fluoro-2-nitro-4-(trifluoromethyl)benzene was selected since the derivatization effectively shifted the absorption wavelength to the visible region (400-450nm), where most drug substances, impurities and even the derivatization reagent absorb very weakly. Due to the redshift effect, interference was minimized and adequately low limits of quantitation were reached (0.24-0.80nmol/mL). Moreover, the derivatization reaction was readily carried out in dimethyl sulfoxide at room temperature for 1h using N,N-diisopropylethylamine as catalyst to achieve the highest yield. Without any pre-treatment, the derivatives were analyzed by high-performance liquid chromatography with diode array detection. The high stability of the derivatives within 24h at room temperature (RSD<1.04%) further facilitated the simultaneous preparation and consecutive analysis of quantities of samples. Finally, the proposed method was successfully applied for residue determination of eight aliphatic amines simultaneously in eight drug substance samples. This study could be helpful for the routine analysis and residue control of aliphatic amines in drug substances.

Combined dispersive solid-phase extraction-dispersive liquid–liquid microextraction-derivatization for gas chromatography–mass spectrometric determination of aliphatic amines on atmospheric fine particles

Short-chain aliphatic amines are ubiquitous in the atmospheric environment. They play an important role in the formation and growth of atmospheric particles. As such, there is a pressing need to monitor these particle-bound compounds present at trace quantities. The present work describes an efficient, one-step microextraction technique for the preconcentration and detection of trace levels of 10 aliphatic amines on fine particles (particulate matter of 2.5μm or less (PM2.5)) in the atmosphere. After extraction of amines from particles in acidified water samples, carbon-based sorbents (in dispersive solid-phase extraction mode), and vortex agitation were utilized for simultaneous derivatization-extraction and dispersive liquid–liquid microextraction. The approach significantly increased the recoveries and enrichment of the amine derivatives. This one-step, combined technique is proposed for the first time. Several influential factors including type and concentration of derivatization reagent (for gas chromatographic separation), type of buffer, sample pH, types and volumes of extraction and disperser solvents, type and amount of sorbent, vortex time and temperature, desorption solvent type and volume, and salt content were investigated and optimized. Under the optimum conditions, high enrichment factors (in the range of between 307 and 382) and good reproducibility (relative standard deviations, below 7.0%, n=5) were achieved. The linearity ranged from 0.1μg/L–100μg/L, and from 0.5μg/L–100μg/L, depending on the analytes. The limits of detection were between 0.02μg/L (corresponding to ∼0.01ng/m3 in air) and 0.09μg/L (corresponding to ∼0.04ng/m3 in air). The developed method was successfully applied to the analysis of PM2.5 samples collected by air sampling through polytetrafluoroethylene filters. The concentration levels of amines ranged from 1.04 to 4.16ng/m3 in the air sampled.

A facile and fully automated on-fiber derivatization protocol for direct analysis of short-chain aliphatic amines using a matrix compatible solid-phase microextraction coating

Solid-phase microextraction (SPME) analysis of short-chain aliphatic amines (C3-C6) in aqueous solutions was investigated using pentafluorobenzaldehyde (PFBAY) as on-fiber derivatization reagent. A standard gas generating vial agent was used for on-fiber loading of the derivatization agent so as to avoid the need for its regeneration at each derivatization cycle. Several parameters such as loading time, reaction temperature, and reaction/extraction time were optimized for headspace and direct sampling in aqueous solutions. Three different coating chemistries were tested and their performances compared in order to achieve the best compromise between sensitivity and analysis throughput. The newly developed PDMS/DVB/PDMS coating showed superior performance in terms of extraction efficiency while the capability to prevent on-fiber degradation of the derivatizing products. The optimized method was used for quantitation of short-chain aliphatic amines in aqueous samples and provided detection limits in the low ppb range for all the amines tested with accuracy values between 79 and 120%. The method was applied towards the analysis of environmental water samples and the accuracy of the results was evaluated by different calibration approaches.

Novel one-step headspace dynamic in-syringe liquid phase derivatization–extraction technique for the determination of aqueous aliphatic amines by liquid chromatography with fluorescence detection

A novel one-step headspace (HS) dynamic in-syringe (DIS) based liquid-phase derivatization–extraction (LPDE) technique has been developed for the selective determination of two short-chain aliphatic amines (SCAAs) in aqueous samples using high performance liquid chromatography (HPLC) with fluorescence detection (FLD). Methylamine (MA) and dimethylamine (DMA) were selected as model compounds of SCAAs. In this method, a micro-syringe pre-filled with derivatizing reagent solution (9-fluorenylmethyl chloroformate) in the barrel was applied to achieve the simultaneous derivatization and extraction of two methylamines evolved from alkalized aqueous samples through the automated reciprocated movements of syringe plunger. After the derivatization–extraction process, the derivatized phase was directly injected into HPLC-FLD for analysis. Parameters influencing the evolution of methylamines and the HS-DIS-LPDE efficiency, including sample pH and temperature, sampling time, as well as the composition of derivatization reagent, reaction temperature, and frequency of reciprocated plunger movements, were thoroughly examined and optimized. Under optimal conditions, detections were linear in the range of 25–500μgL−1 for MA and DMA with correlation coefficients all above 0.995. The limits of detection (based on S/N=3) were 5 and 19ngmL−1 for MA and DMA, respectively. The applicability of the developed method was demonstrated for the determination of MA and DMA in real water samples without any prior cleanup of the sample. The present method provides a simple, selective, automated, low cost and eco-friendly procedure to determine aliphatic amines in aqueous samples.

Analysis of short‐chain aliphatic amines in food and water samples using a near infrared cyanine 1‐(ε‐succinimydyl‐hexanoate)‐1′‐methyl‐3,3,3′,3′‐tetramethyl‐indocarbocyanine‐5,5′‐disulfonate potassium with CE–LIF detection

Precolumn derivatization of six short-chain aliphatic amines by a near-infrared dye, 1-(ε-succinimydyl-hexanoate)-1'-methyl-3,3,3',3'-tetramethyl-indocarbocyanine-5,5'- disulfonate potassium (MeCy5-OSu), followed by MEKC-CE-LIF detection has been developed as a method for the determination of aliphatic amines in environmental water and food. Optimum derivatization was operated nicely in pH 9.0 borate buffer at 20°C for 30 min. Well separated peaks were observed with a pH 9.5 BGE containing 10 mmol L⁻¹ phosphoric acid, 20 mmol L⁻¹ SDS, and 7% methanol buffered with 1.0 mol L⁻¹ NaOH. The separation procedure was rapidly achieved within 11 min and the matrix interferences could be effectively eliminated. A linear calibration graph was obtained for 5-200 nmol L⁻¹ analytes with a correlation coefficient in the range 0.9933-0.9995 for amines. This method was successfully utilized to determine aliphatic amines in lake, sewage water, and red wine with recoveries ranging from 96.4 to 105% and the RSDs ranging from 0.9 to 2.9%. Near-infrared, LIF-detector-compatible MeCy5-OSu was proved suitable for the accurate, sensitive, and rapid separation and determination of aliphatic amines in water and food samples.

Determination of aliphatic amines by gas chromatography–mass spectrometry after in-syringe derivatization with pentafluorobenzoyl chloride

A simple and highly sensitive gas chromatographic method has been developed for the determination of low molecular weight short-chain aliphatic amines (SCAAs) after their simultaneous extraction and in-syringe derivatization with pentafluorobenzoyl chloride (PFBOC). Derivatization of the low molecular weight aliphatic amines in bicarbonate buffer of pH 10.5 with PFBOC was followed by immersed solvent microextraction. Derivatization conditions, including reagent concentration, reaction pH, ionic concentration of buffer, reaction time, stirring rate, reaction temperature and extraction solvent, have been investigated for method optimization. Linearity was studied within range of 0.15 pg ml −1–50 ng ml −1. The correlation coefficients were between 0.9934 and 0.9999. Detection limit of derivatized amines proved to be in the range of 0.117–1.527 pg ml −1, and the intraday and interday relative standard deviation (RSD) values were less than 8% with respect to peak area. The method was applied for analysis of lake, river and industrial waste water. The recoveries of extraction from lake, river and industrial waste water samples, which have been spiked with different levels of aliphatic amines, were in the range of 68–99%, 63–102% and 62–105%, respectively.

Simultaneous Derivatization and Extraction of Primary Short-chain Aliphatic Amines Using an Ultrasonic-mixed Water-ionic Liquid Two-phase System for Liquid Chromatography

Here, we report on a procedure in which ultrasonic waves were used to mix a water-ionic liquid two-phase system to simultaneously derivatize amines with dansyl chloride and extract, and the resulting dansyl amines into an ionic liquid (IL) at room temperature within 15 min. The ILs used were room-temperature ionic liquids (RTILs), such as 1-alkyl-3-methylimidazolium hexafluorophosphate ([C(n)MIM][PF(6)], n = 4, 6, 8), which are insoluble in water, and can extract more than 88% of the total dansyl amines (Dns-amines) present in aqueous solution. The Dns-amines formed were separated by chromatography in 20 µL of RTIL in a mobile-phase gradient of acetonitrile-water flowing through an Agilent Zorbax SB-C18 column. The eluents were analyzed at 333 nm using a UV detector. The optimal analytical conditions were achieved by using the following: RTILs with a 4-carbon alkyl chain; a 7-mL water sample and 1 mL each of 5 mM dansyl chloride in acetone and 20 mM sodium tetraborate buffer for use with a fixed volume (1 mL) of IL; buffer pH of 10.4; duration of 15 min; and an acetonitrile-water ratio of 50:50 from zero time to 3 min, 80:20 from 4 to 10 min, and 50:50 from 11 to 16 min. In comparison to the single-phase hot-water (70°C) derivatization process reported earlier, the simultaneous process developed here showed a higher derivatization efficiency at the tested concentration. The linear range of analysis (0.14-7.14 mg/L) was determined, and the correlation coefficient (R) ranged from 0.9878 to 0.9980. Furthermore, the estimated percentage of recovery from amine-spiked river-water samples ranged from 76 to 108%. The method presented here is simple and fast, and does not involve the use of volatile organic extractants.

On-line determination of aliphatic amines in water using in-tube solid-phase microextraction-assisted derivatisation in in-valve mode for processing large sample volumes in LC

This paper describes a cost-effective procedure for the analysis of short-chain aliphatic amines in water samples using a solid-phase microextraction device. Analyte preconcentration and derivatisation were effected into a capillary column coated with 95% polydimethylsiloxane-5% polydiphenylsiloxane, which was used as the injection loop of a Rheodyne injection valve. The coating was previously loaded with the derivatisation reagent, 9-fluorenylmethyl chloroformate. A volume of 1 mL of samples was then drawn into the capillary column, and the extracted analytes were left to react on the capillary coating for 5 min. Next, the capillary column was cleaned by passing water. Finally, the injection valve was rotated, and the derivatives formed were dynamically desorbed and transferred to the analytical column into the mobile phase. Methylamine, ethylamine, propylamine, n-butylamine and n-pentylamine were selected as model compounds. Excellent sensitivity was achieved, being the limits of detection of 15-200 microg/L when using UV detection and of 0.1-0.4 microg/L by fluorescence.

Fast field analysis of short‐chain aliphatic amines in water using solid‐phase microextraction and a portable gas chromatograph

A novel method is firstly presented for field and rapid analysis of short-chain aliphatic amines in water as their pentafluorobenzaldehyde (PFBAY) derivative using solid-phase microextraction (SPME) and portable GC. In the proposed method, short-chain aliphatic amines in water rapidly reacted with PFBAY, and then were headspace extracted and concentrated by SPME. The formed amines derivatives were analyzed by portable GC. The SPME parameters of fiber selection, extraction temperature, extraction time, and stirring rate were studied. The method validations including LOD, recovery, precision, and linearity were studied. It was found that the proposed method required the whole analysis time 22 min, and provided low LOD of 1.2-4.6 ng/mL, good recovery of 91-106%, good precision of RSD value 3.5-9.3%, and linear range 20.0-500 ng/mL (r(2) >0.99). The obtained results demonstrated that the SPME-portable GC is a simple, rapid, and efficient method for the field analysis of short-chain aliphatic amines. Finally, the proposed method was further applied to the quantification of ethylamine, propylamine, and butylamine in environmental water.

Trace determination of short-chain aliphatic amines in biological samples by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection

In this study, a new capillary electrophoresis (CE) method is described originally for the sensitive and selective determination of short-chain aliphatic amines in biological samples. These amines were converted into their N-hydroxysuccinimidyl fluorescein- O-acetate (SIFA) derivatives and measured by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection. The derivatization conditions and separation parameters for the aliphatic amines were optimized in detail. The SIFA-labeled amines were fully separated within 8.5 min using 25 mM pH 9.6 boric acid electrolyte containing 60 mM sodium dodecyl sulfate (SDS). The parameters of validation such as linearity of response, precision and detection limits were determined. The detection limits were obtained in the range from 0.02 to 0.1 nM, which was the lowest value reported by CE methods. The developed method was successfully employed to monitor aliphatic amines in serum and cells samples. After comparison of other CE methods using different fluorescent probes, the present method represents a powerful tool for the trace determination of aliphatic amines in complex biological samples.

Theoretical and Experimental Studies of the Inclusion Phenomena of β‐Cyclodextrin with Organic Amines

AbstractThe inclusion complexations of β‐cyclodextrin (β‐CD) with ethylenediamine 1 and its three analogs, diethylenetriamine 2, triethylamine 3 and ethylene diaminetetraacetic acid 4 were examined by means of both experimental measurements and theoretical calculations. From the polarimetric method, it was found that β‐CD could form 1/1 host‐guest inclusion complexes with these guests, and the formation constants (K) of the inclusion complexes have also been determined in aqueous solution at 298.2 K. Semiempirical PM3 calculations were carried out to assess the intermolecular binding ability of β‐CD to a series of short chain aliphatic amines such as guests 1–7, cyclic aliphatic amines 8–11, and aromatic amines 12–13. The interaction processes between β‐CD and the guests were reported, and the complexation differences of β‐CD with these guests also discussed. The energy contribution from deformation energy or hydrate energy to interaction energy in the inclusion systems was found to be quite small. The stability of β‐CD inclusion complexes depended on the size fit between the host and guest. For β‐CD complexes of guests 1–4, the order of the K values from the polarimetric measurements is in good accordance with that of the absolute values of the complexation energies from PM3 calculations.

A microanalytical method for ammonium and short-chain primary aliphatic amines using precolumn derivatization and capillary liquid chromatography

A new microscale method is presented for the determination of ammonium and primary short-chain aliphatic amines (methylamine, ethylamine, propylamine, n-butylamine and n-pentylamine) in water. The assay uses precolumn derivatization with the reagent o-phthaldialdehyde (OPA) in combination with the thiol N-acetyl- l-cysteine (NAC), and capillary liquid chromatography with UV detection at 330 nm. The described method is very simple and rapid as no preconcentration of the analytes is necessary, and the volume of sample required is only 0.1 mL. Under the proposed conditions good linearity has been obtained up to a concentration of the analytes of 10.0 mg L −1, the limits of detection being of 8–50 μg L −1. No matrix effect was found, and recoveries between 97 and 110% were obtained. The precision of the method was good, and the achieved variation coefficients were below 12%. The reliability of the proposed approach has been tested by analyzing a microsample of fogwater collected from leaf surfaces.

Short-chain aliphatic amines in human urine: a mathematical examination of metabolic interrelationships

The relationships between several small molecular weight aliphatic amines (methylamine, dimethylamine, trimethylamine, and ethylamine) and an associated N-oxide (trimethylamine N-oxide) quantified in human urine collected from 203 healthy volunteers have been assessed mathematically. Principal component analysis highlighted a female subgroup with raised trimethylamine levels and the possibility of hormonal influence on the N-oxidation of trimethylamine has been proposed. A second subgroup of men, who ate a large meal of fish before the study, displayed raised levels of all compounds except ethylamine. In all cases, ethylamine was least significantly correlated with the other urinary components and appeared metabolically unrelated.

Development of gas chromatography–mass spectrometry following headspace single-drop microextraction and simultaneous derivatization for fast determination of short-chain aliphatic amines in water samples

In this work, for the first time, gas chromatography–mass spectrometry (GC–MS) following headspace single-drop microextraction (HS-SDME) and simultaneous derivatization was developed for fast determination of short-chain aliphatic amines (SCAAs) in water samples. In the proposed method, SCAAs in water samples were headspace extracted and concentrated by suspending a microdrop of solvent, and SCAAs extracted in the microdrop of solvent were simultaneously and rapidly reacted with pentafluorobenzaldehyde (PFBAY). The formed SCAA derivatives were analyzed by GC–MS. The HS-SDME parameters of solvent selection, solvent volume, sample temperature, extraction time and stirring rate were studied, and the method linearity, precision and detection limits, were also studied. The results show that the proposed method provided good linearity ( R 2 > 0.99, 5.0–500 ng/ml), low detection limit (0.6–1.1 ng/ml), and good precision (RSD value less than 10%). The proposed method was further tested by its application to quantitative analysis of SCAAs in four wastewater samples. The experiment results have demonstrated that GC–MS following HS-SDME and simultaneous derivatization is a simple, rapid and low-cost method for the determination of SCAAs in water samples.

Involvement of Semicarbazide-Sensitive Amine Oxidase-Mediated Deamination in Lipopolysaccharide-Induced Pulmonary Inflammation

Semicarbazide-sensitive amine oxidase (SSAO) resides on the vascular endothelium and smooth muscle cell surface and is capable of deaminating short chain aliphatic amines and producing toxic aldehydes and hydrogen peroxide. The enzyme, also known as a vascular adhesion protein-1, is involved in the inflammation process. This intriguing protein with dual functions is increased in the serum of diabetic and heart failure patients. In the present study we assessed the involvement of SSAO in a lipopolysaccharide-induced pulmonary inflammation model using transgenic mice that overexpress human vascular adhesion protein-1. Overexpression of SSAO activity increased the formation of protein-formaldehyde deposits in tissues. Lysine residues of proteins were the primary targets for cross-linkage with formaldehyde derived from deamination of methylamine. Lipo-polysaccharide-induced increases in inflammatory cells in the bronchoalveolar lavage (BAL) fluid were significantly higher in the transgenic than in the nontransgenic mice. BAL cell counts were also higher in the untreated transgenic than in nontransgenic mice. Blocking SSAO activity with a selective inhibitor significantly reduced the number of neutrophils as well as levels of macrophage inflammatory protein-1alpha, granulocyte colony-stimulating factor, tumor necrosis factor-alpha, and interleukin-6 in the BAL fluid. Inhalation of methylamine also increased BAL neutrophil counts. Together, these results suggest a role for SSAO-mediated deamination in pulmonary inflammation.

An evaluation of solid phase microextraction for aliphatic amines using derivatization with 9-fluorenylmethyl chloroformate and liquid chromatography

The reliability of SPME combined with a chemical reaction for the analysis of short-chain aliphatic amines by liquid chromatography has been investigated. Different options to couple SPME and derivatization have been tested and compared: (i) derivatization of the analytes in solution followed by the extraction of the derivatives, (ii) extraction of the analytes and subsequent derivatization by immersing the SPME fibre onto a solution of the reagent, and (iii) extraction/derivatization of the analytes using fibres previously coated with the reagent. Methylamine (MA), dimethylamine (DMA) and trimethylamine (TMA) have been selected as a model of primary, secondary and tertiary amines, respectively. The analytes have been derivatized with the fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC), and the fibre coating was Carbowax-templated resin (CW-TR). The employment of fibres coated with FMOC to extract and derivatize the analytes was the best option, as compared with the other approaches tested the sensitivity was considerably improved. On the basis of these studies, a new procedure for the determination of MA, DMA and TMA in water is presented. To demonstrate the utility of the proposed conditions data on linearity, accuracy, repeatability and sensitivity are given. Results of the determination of the amines in tap, river and waste water are also presented.

Selective determination of trimethylamine in air by liquid chromatography using solid phase extraction cartridges for sampling

The selective determination of trimethylamine (TMA) in air by liquid chromatography is reported. Sampling is effected by flushing air through C 18-packed solid-phase extraction (SPE) cartridges at a flow rate of 15 mL/min for 15 min. Next, TMA is desorbed from the cartridges and injected into the chromatographic system. The analyte is then selectively retained on a precolumn ( 20 mm×2.1 mm i.d., packed with 30 μm, Hypersil C 18 phase), and derivatized on-line by injecting 9-fluorenylmethyl chloroformate (FMOC). Finally, the TMA-FMOC derivative is transferred to the analytical column ( 125 mm×4 mm i.d., LiChrospher 100 RP 18, 5 μm), and monitored at 262 nm. The method was applied to the measurement of TMA in air in the 0.25–2.5 μg interval (equivalent to concentrations of TMA of 1.1–11 mg/m 3), providing good linearity, reproducibility and accuracy. The mean recovery of TMA was (96±7%) ( n=12), and the limit of detection was 0.05 μg. The proposed procedure allows the selective determination of TMA in the presence of other primary and secondary short-chain aliphatic amines.