Chemical constituents and larvicidal activity of Hymenaea courbaril fruit peel

The chemical compositions of the essential oils from the peel of ripe and unripe fruits of Hymenaea courbaril L., obtained by hydrodistillation, were analyzed by GC and GC-MS. The main constituents of the essential oil from the peel of the ripe fruits were the sesquiterpenes alpha-copaene (11.1%), spathulenol (10.1%) and beta-selinene (8.2%), while germacrene-D (31.9%), beta-caryophyllene (27.1%) and bicyclogermacrene (6.5%) were the major compounds in the oil from unripe fruits. The essential oils were tested against Aedes aegypti larvae and showed LC50 values of 14.8 +/- 0.4 microg/mL and 28.4 +/- 0.3 microg/mL for the ripe and unripe fruit peel oils, respectively. From the peel of the ripe fruits, the diterpenes zanzibaric acid and isoozic acid were isolated, along with the sesquiterpene caryolane-1,9beta-diol. To the best of our knowledge, this is the first report of this sesquiterpene in the genus. The structures of all compounds isolated were identified on the basis of their spectral data (IR, MS, 1D- and 2D-NMR) and by comparison with literature spectral data.     

Phytochemical analysis and in vitro antimicrobial and free-radical-scavenging activities of the essential oils from Euryops arabicus and Laggera decurrens

The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the identification of 48 and 44 compounds for both plants, respectively. The essential oil of E. arabicus was rich in oxygenated sesquiterpenes (39.9%). The oil also contained a high content of sesquiterpene hydrocarbons (24.1%). Compounds such as caryophyllene oxide (8.6%), T-cadinol (7.0%), spathulenol (5.2%), (E)-β-caryophyllene (6.0%) and 2-epi-(E)-β-caryophyllene (6.0%) were the main constituents of the oil. Oxygenated monoterpenes also predominated in L. decurrens (46.3%). The thymoquinone-derivative, 3-methoxy-2-methyl-5-(1-methylethyl)-2,5-cyclohexadiene-1,4-dione (28.1%), thymol (5.7%) and eudesma-11-en-4a-ol (7.0%) were the most abundant constituents. Both essential oils showed antimicrobial activity with MIC-values between 0.13-5.25 mg/mL. Furthermore, only the essential oil of L. decurrens exhibited a strong antioxidant activity (91%) at 500 μg/mL.     

Constituents of south Indian vetiver oils

The essential oils isolated from vetiver [Vetiveria zizanioides (L.) Nash.] roots collected from four locations in south India were analyzed by GC-FID and GC-MS. Eighty constituents, representing 94.5-97.8% of the oils, have been identified. The oils from Bangalore, Hyderabad, Kundapur, and Mettupalayam were rich in sesquiterpenes and oxygenated sesquiterpenes with cedrane, bisabolane, eudesmane, eremophilane, and zizaane skeletons. The main components of the four essential oils were: eudesma-4,6-diene (delta-selinene) + beta-vetispirene (3.9-6.1%), beta-vetivenene (0.9-9.4%), 13-nor-trans-eudesma-4(15),7-dien-11-one + amorph-4-en-10-ol (5.0-6.4%), trans-eudesma-4(15),7-dien-12-ol (vetiselinenol) + (E)-opposita-4(15),7(11)-dien-12-ol (3.7-5.9%), eremophila-1 (10),11-dien-2alpha-ol (nootkatol) + ziza-6(13)-en-12-ol (khusimol) (16.1-19.2%), and eremophila-1(10),7(11)-dien-2alpha-ol (isonootkatol) + (E)-eremophila-1(10),7(11)-12-ol (isovalencenol) (5.6-6.9%). The important compounds that impart the characteristic vetiver odor are: khusimene, delta-selinene, beta-vetivenene, cyclocopacamphan-12-ol (epimers A and B), vetiselinenol, khusimol, isovalencenol, khusimone, alpha-vetivone, and beta-vetivone. The chemical profiles of the oils are comparable to Haitian vetiver oil.     

Antioxidant activity of crude extracts and essential oils from flower buds and leaves of Cistus creticus and Cistus salviifolius

Volatile oils from flowers and leaves of C. creticus L. and C. salviifolius L. were extracted by two extraction methods; namely, hydrodistillation and solid-phase micro-extraction (SPME). The chemical composition of essential oils was analyzed by GC and GC–MS. The volatile extracted from leaves and flowers of C. criticus using SPME was dominated by monoterpenes and sesquiterpenes hydrocarbon with α-pinene, camphene and α-cubebene as major components. In hydrodistillation, the oil extracted from leaves was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and sclarene as major components, whereas, the oil extracted from flowers was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and abietatriene as major components. The volatile from flowers and leaves of C. salviifolius obtained by SPME were dominated by monoterpenes and sesquiterpenes with δ-3-carene, α-pinene, β-pinene, and E-caryophyllene as major constituents. On the other hand, the oils from flowers and leaves of C. salviifolius obtained by hydrodistillation were dominated by oxygenated diterpenes, diterpenes hydrocarbon and esters with dehydro abietol, abietol, manoyl oxide and methyl octadecenoate as major components. In the leaves, the major components of the oil were manoyl oxide, E-ethyl cinnamate, and Z-ethyl cinnamate. These oils showed weak antioxidant activity when compared to the positive controls α-tocopherol, ascorbic acid, and EDTA, while the crude extracts aq. MeOH, butanol, and water showed good antioxidant activity. Discriminating between the studied plants based on the extraction method was also possible upon applying Principle component analysis (PCA) to the obtained GC–MS data.     

Variation in essential oil composition of Teucrium hircanicum L. from Iran-A rich source of (E)-α-bergamotene

In present work, the chemical composition of the essential oils obtained from dried flowering aerial parts of Teucrium hircanicum L. (Labiatae) originated from ten wild populations in Iran was analyzed by a GC-FID and GC/MS system. The oil yields varied from 0.04% to 0.1%. A total of thirty-two compounds representing 67.6–97.7% of the oil were identified. The essential oil was found to be rich in sesquiterpene hydrocarpons (E)-α-bergamotene (17.5–86.9%) and (E)-β-farnesene (0.5–21.4%). Of the total identified compounds, sesquiterpene hydrocarpons (36.1–89.7%) were included the greatest essential oil fraction in all the populations, followed by oxygenated monoterpenes (2.2–21.6%), oxygenated sesquiterpenes (0.0–14.4%) and monoterepene hydrocarbons (0.0–9.5%). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used to distinguish any geographical variations, indicating that the clustering of populations is related to their geographic origin. According to the GC/MS analysis, two chemotypes consisting of (E)-α-bergamotene and (E)-α-bergamotene-(E)-β-farnesene were identified in the populations.     

Antifungal activity of essential oil from Asteriscus graveolens against postharvest phytopathogenic fungi in apples

The essential oils of the aerial parts of Asteriscus graveolens have been studied using GC and GC-MS. Twenty-eight compounds were identified in the essential oil amounting to 94.9% of the total oil. The aerial part oils showed similar chromatographic profiles and were characterized by having a high content of oxygenated sesquiterpenes with 6-oxocyclonerolidol (66.7% +/- 5.5) and 6-hydroxycyclonerolidol (8.8% +/-1.2) as the major components. The antifungal effect of the essential oil from A. graveolens leaves was evaluated in vitro against three phytopathogenic fungi of apples (Alternaria sp., Penicillium expansum, and Rhizopus stolonifer). The results suggest that this essential oil has fungicidal properties towards Alternaria sp. from direct contact assay at 0.2% (v/v) and to P. expansum from vapor assay tests at 80 microL.     

Preliminary Study on Phytochemical Constituents and Biological Activities of Essential Oil from Myriactis nepalensis Less.

In response to the need for novel therapeutic strategies to combat the development of microbial resistance, plant essential oils may represent a promising alternative source. This study set out to characterize the chemical composition and assess the antibacterial potential of Myriactis nepalensis Less. essential oil (MNEO). Essential oil isolated from M. nepalensis by hydrodistillation was analyzed using a GC–MS technique. The antibacterial properties of MNEO alone and combined with antibiotics (chloramphenicol and streptomycin) were tested via the disc diffusion, microbroth dilution, and checkerboard methods. MNEO was represented by oxygenated sesquiterpenes (60.3%) and sesquiterpene hydrocarbons (28.6%), with caryophyllene oxide, spathulenol, humulene epoxide II, β-elemene, neointermedeol, and β-caryophyllene as the main compounds. MNEO exhibited a strong antibacterial effect against Gram-positive bacteria, with MIC and MBC values of 0.039 mg/mL and 0.039–0.156 mg/mL, respectively, and synergistic effects were observed in both combinations with chloramphenicol and streptomycin. Furthermore, the antibiofilm and cytotoxic activities of MNEO were also evaluated. The crystal violet assay was used for quantification of Staphylococcus aureus biofilm formation, and an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay was conducted to determine cell viability. The results revealed MNEO could dose-dependently inhibit Staphylococcus aureus biofilm formation and possessed potential cytotoxic on both normal and cancer cells (IC₅₀ values from 13.13 ± 1.90 to 35.22 ± 8.36 μg/mL). Overall, the results indicate that MNEO may have promising applications in the field of bacterial infections.     

Chemical investigation of the essential oil from berries and needles of common juniper (Juniperus communis L.) growing wild in Estonia

The essential oils obtained by simultaneous distillation and extraction (SDE) from the fresh and dried needles and dried berries of Juniperus communis L. of Estonian origin were subjected to GC-FID and GC-MS analyses. The yields of the oils ranged between 0.2% and 0.6% from juniper berries and between 0.5% and 1.0% from needles (dried weight). A total of 87 compounds were identified, representing over 95% of the oil. The major compounds in the needle oil were monoterpenes α-pinene (33.3-45.6%), sabinene (0.2-15.4%), limonene (2.8-4.6%) and sesquiterpenes (E)-β-caryophyllene (0.8-10.3%), α-humulene (0.8-6.2%) and germacrene D (3.0-7.8%). The juniper berry oil was rich in α-pinene (53.6-62.3%), β-myrcene (6.5-6.9%) and germacrene D (4.5-6.1%). The main oxygenated terpenoids found in the needle oil were germacrene D-4-ol (0.4-4.0%) and α-cadinol (to 2.7%). The oil from fresh needles contained high amounts of (E)-2-hexenal (3.7-11.7%).     

Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K⁺ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.     

Anti-acetylcholinesterase and antioxidant activity of essential oils from Hedychium gardnerianum Sheppard ex Ker-Gawl

Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC(50) values of approximately 1 mg/mL, showing no statistical differences between collection sites. Three oils presented mixed inhibition, whilst one was almost truly competitive. This activity can be attributed to the presence of sesquiterpenes, which constituted more than 60% of the composition of the oils. Regarding the antioxidant activity as measured by the DPPH method, all the oils presented activities similar to reference compounds, although with statistical differences between collection sites. Cytotoxicity measured using Artemia salina classified these oils as moderately toxic, with LC(50) values ranging from 300 to 500 μg/mL. These results indicate a possible application of these oils in aromatherapy as coadjuvants in the treatment of cognitive diseases such as Alzheimer, since they may contribute to increase acetylcholine in cholinergic neurons and simultaneously fight deleterious oxidations responsible by neurological degeneration.     

GC×GC/qMS analyses of Campomanesia guazumifolia (Cambess.) O. Berg essential oils and their antioxidant and antimicrobial activity

The present study investigated the essential oil obtained from Campomanesia guazumifolia (Cambess.) O. Berg, an aromatic plant used in Brazilian folk medicine. The chemical composition was performed by GC×GC/qMS. The antioxidant and antimicrobial activities were evaluated by DPPH and BCB and, MIC assays, respectively. Sixty-eight compounds were identified in the oil, where the major compounds were bicyclogermacrene (15%), globulol (5%) and spathulenol (5%). Sesquiterpene hydrocarbons (29 compounds) and oxygenated sesquiterpenes (20 compounds) were the most representative classes of terpenes. DPPH (IC₅₀ value 26.1 ± 0.5 μg/mL) and BCB (68.3 ± 1.5%) values indicated a significant antioxidant activity. The essential oil strongly inhibited Staphylococcus aureus (MIC 15 ± 0.1 μg/mL), Escherichia coli (MIC 25 ± 0.2 μg/mL) and Candida albicans (MIC 5 ± 0.1 μg/mL). The results give a deeper understanding of the chemical composition and report for the first time the antioxidant and antimicrobial potential of the C. guazumifolia essential oil.     

Volatile constituents of two species of Protium from the Atlantic rainforest in the state of Pernambuco, Brazil

The chemical composition of the essential oils from Protium giganteum and P. aracouchine was determined, for the first time, using GC-MS analysis. From the oil of P. giganteum, 32 components were identified, representing 93.9% of the oil, and from P. aracouchine, 29 components, representing 97.8% of the oil. Among the compounds identified in the P. giganteum oil, 93.6% were sesquiterpenes, with beta-caryophyllene (26.0 +/- 0.8%), globulol (9.3 +/- 0.2%), alpha-cadinol (7.0 +/- 0.5%), alpha-humulene (6.4 +/- 0.1%) and germacrene D (6.2 +/- 0.3%) as the major components. Among the 29 compounds identified in the P. aracouchine oil, 95.9% were sesquiterpenes as well, with spathulenol (31.8 +/- 1.6%), alpha-cis-bergamotene (8.8 +/- 0.2%) and viridiflorol (9.7 +/- 0.7%) as the major components.     

Chemical Composition and Antifungal Activity of Myrcia multiflora and Eugenia florida Essential Oils

The essential oils of three specimens of Myrcia multiflora (A, B and C) and Eugenia florida were extracted by hydrodistillation, and the chemical compositions from the essential oils were identified by gas chromatography and flame ionization detection (CG/MS and CG-FID). The fungicide potential of the EOs against five fungicide yeasts was assessed: Candida albicans INCQS-40175, C. tropicalis ATCC 6258, C. famata ATCC 62894, C. krusei ATCC 13803 and C. auris IEC-01. The essential oil of the specimen Myrcia multiflora (A) was characterized by the major compounds: α-bulnesene (26.79%), pogostol (21.27%) and δ-amorphene (6.76%). The essential oil of the specimen M. multiflora (B) was rich in (E)-nerolidol (44.4%), (E)-γ-bisabolene (10.64%) and (E,E)-α-farnesene (8.19%), while (E)-nerolidol (92.21%) was the majority of the specimen M. multiflora (C). The sesquiterpenes seline-3,11-dien-6-α-ol (12.93%), eremoligenol (11%) and γ-elemene (10.70%) characterized the chemical profile of the EOs of E. florida. The fungal species were sensitive to the essential oil of M. multiflora (B) (9–11 mm), and the lowest inhibitory concentration (0.07%) was observed in the essential oil of M. multiflora (A) against the yeasts of C. famata. Fungicidal action was observed in the essential oils of M. multiflora (A) against C. famata, with an MIC of 0.78 µL/mL and 3.12 µL/mL; C. albicans, with an MFC of 50 µL/mL and M. multiflora (C) against C. albicans; and C. krusei, with a MFC of 50 µL/mL.     

Antioxidant capacity and larvicidal and antifungal activities of essential oils and extracts from Piper krukoffii

The leaves and twigs of Piper krukoffii, collected in the Carajás National Forest, north Brazil, yielded essential oils (2.0% and 0.8%), the main constituents of which were myristicin (40.3% and 26.7%), apiole (25.4% and 34.1%) and elemicin (2.8% and 3.0%). The antioxidant activities of the oils, methanol extract and its sub-fractions were evaluated. The DPPH EC50 values varied from the ethyl acetate sub-fraction (73.4 +/- 3.7 microg/mL) to the methanol extract (24.9 +/- 0.8 microg/mL), and the ABTS TEAC values ranged in the same order from 265.7 to 349.2 microMol TE/g. These results indicated a significant antioxidant activity for the plant. The lignans (-)-kusunokin, yatein, (-)-hinokin and cubebin were identified in the methanol extract. The hydro-methanolic sub-fraction showed a high value for total phenol content (106.5 +/- 0.7 mg GAE/g), as well as 1H NMR signals for sugar moieties. Crude extracts and sub-fractions were also able to inhibit beta-carotene bleaching, varying from 22.4 to 47.1%. The oils from the leaves and twigs showed strong larvicidal (21.4 and 3.6 microg/mL) and fungicide (0.5 and 0.1 microg/mL) activities.     

Intraspecific variation in the essential oils from Drimys brasiliensis leaves and stem barks

The essential oils from leaves and stem barks of Drimys brasiliensis Miers (Winteraceae), collected in July and December 2008, were analyzed by GC/FID and GC/MS. The stem bark oils were composed mainly of monoterpenes (July, 45 +/- 3%; December, 92 +/- 4%), while the oils from leaves showed the predominance of sesquiterpenes (July, 47 +/- 1%; December, 55 +/- 1%). The variation in the relative amount of constituents could be associated, at least in part, to several microclimatic parameters such as precipitation, temperature and/or phenological state, which were different for each collection of D. brasiliensis.     

Phytochemical analysis of the essential oil of Achillea millefolium L. from various European Countries

Variations in the essential oil composition of Achillea millefolium L. growing in Estonia and in other European countries, were determined. The oils were obtained in yields of 0.9-9.5 mL kg-1. A total of 102 components were identified. The quantitatively most important components of yarrow were sabinene, beta-pinene, 1,8-cineole, artemisia ketone, linalool, alpha-thujone, beta-thujone, camphor, borneol, fenchyl acetate, bornyl acetate, (E)-beta-caryophyllene, germacrene D, caryophyllene oxide, beta-bisabolol, delta-cadinol, chamazulene etc. Samples from Estonia contained high amounts of monoterpenes and chamazulene. High amounts of monoterpenes and chamazulene were also found in samples from Hungary, Greek, Moldavia, Latvia, Lithuania and Germany. The oils from France, Belgium, Russia, Armenia, Spain and Italy were rich in oxygenated monoterpenes and contained a little amount of chamazulene. The drugs from Greece, Estonia, Moldavia and Scotland were rich in sesquiterpenes. The Millefolii herba grown in Estonia conforms to the European Pharmacopoeia (EP) standards in the aspect of the essential oil contents.     

Volatile oil composition of Pogostemon heyneanus and comparison of its composition with patchouli oil

The volatile oil of the leaves of Pogostemon heyneanus Benth. (Lamiaceae) was analyzed by GC and GC-MS. Twenty-six components representing 96.0% of the oil were identified. The major components of the oil were acetophenone (51.0%), beta-pinene (5.3%), (E)-nerolidol (5.4%), and patchouli alcohol (14.0%). Comparison of the compositions of the oils of P. heyneanus and P. cablin (Blanco) Benth. (Patchouli oil) showed wide variation between them. Though 13 sesquiterpenes and oxygenated sesquiterpenes were detected in both oils, their concentrations in the oils differed widely. Acetophenone, benzoyl acetone and (E)-nerolidol present in the oil of P. heyneanus were not detected in patchouli oil.     

Volatile Composition and Biological Activity of Jordanian Commercial Samples of R. coriaria L. Fruits

The present paper reports the GC-HS-SPME analysis of volatile emission and GC-MS analysis of chemical composition of essential oil of R. coriaria fruits of eight different samples of R. coriaria L. fruits (“sumac” folk name), collected from Jordanian agricultural field and the local market. The analyses show an important variability among the Sumac samples probably due to the origin, cultivation, harvesting period, drying, and conservation of the plant material. The main class of component present in all samples was monoterpenes (43.1 to 72.9%), except for one sample which evidenced a high percentage of sesquiterpene hydrocarbons (38.5%). The oxygenated monoterpenes provided a contribution to total class of monoterpenes ranging from 10.1 to 24.3%. A few samples were rich in monoterpene hydrocarbons. Regarding the single components present in all the volatile emissions, β-caryophyllene was the main compound in most of the analyzed samples, varying from 34.6% to 7.9%. Only two samples were characterized by α-pinene as the main constituent (42.2 and 40.8% respectively). Essential oils were collected using hydro-distillation method. Furfural was the main constituent in almost all the analyzed EOs (4.9 to 48.1%), except in one of them, where β-caryophyllene was the most abundant one. β-caryophyllene ranged from 1.2 to 10.6%. Oxygenated monoterpenes like carvone and carvacrol ranged from 3.2–9.1% and 1.0–7.7% respectively. Cembrene was present in good amount in EO samples EO-2 to EO-8. The antioxidant capacities of the fruit essential oils from R. coriaria were assessed using spectrophotometry to measure free radical scavenger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and inhibition of β-carotene bleaching (BCB). The essential oils from the fruits of the different samples of R. coriaria exhibited the MIC value ranging from 32.8 to 131.25 µg/mL against S. aureus ATCC 6538 and 131.25 to 262.5 µg/mL against E. coli ATCC 8739. The MIC values of ciprofloxacin were 0.59 and 2.34 µg/mL against S. aureus ATCC 6538 and E. coli ATCC 8739, respectively.     

Antibacterial activity of the essential oil and main components of two Dracocephalum species from Iran

The antibacterial activity of Dracocephalum polychaetum and D. surmandinum essential oils and two main components were investigated. Essential oils of the plants were analysed by GC and GC-MS. Twenty-three components were characterised in the essential oil of D. polychaetum. The oil was rich in oxygenated (73.1%) and hydrocarbon (25.0%) monoterpenes including perilla aldehyde (63.4 %) and limonene (22.1%) as the major constituents. From 25 identified compounds (97.8%) in the oil of D. surmandinum perilla aldehyde (54.3%) and limonene (30.1%) were the main constituents. The bioassays exhibited that all of the Gram-positive and Gram-negative bacteria tested were highly inhibited in the presence of the oils and main components investigated. The most sensitive microorganism to the oils was found to be Staphylococcus epidermidis with the lowest MIC value of 0.3?mgmL(-1). The resistant Gram-negative Pseudomonas aeruginosa was highly inhibited by the oil of D. polychaetum with MIC value of 2.4?mgmL(-1).     

Determination of trace amounts of Pd(II) ions in water and road dust samples by flame atomic absorption spectrometry after preconcentration on modified organo nanoclay

This paper describes the application of organo nanoclay, an easily prepared and stable solid sorbent, to the preconcentration of trace amounts of palladium ions in aqueous solution. The organo nanoclay was prepared by adding tetradecyldimethylbenzylamonium chloride onto montmorillonite, which was then modified with 1-(2-pyridylazo)-2-naphthol. The modified nanoclay was used as a solid sorbent for separation and preconcentration of trace amounts of Pd(II) ions, and a simple, sensitive, and economical method was developed for determination of trace amounts of palladium by flame atomic absorption spectrometry. The sorption of Pd(II) ions was quantitative in the pH range of 1.5-5.0, whereas quantitative desorption occurred with 5.0 mL of a mixture containing 1.0 M thiourea and 1.0 M HCl. The RSD of the method was +/- 2.1% (n = 10; concn = 0.5 microg/mL), and the LOD (3sigma(bl); sigma = SD and bl = blank) was 0.1 ng/mL. The calibration curve was linear for concentrations of 0.5-8.0 microg/mL in the initial solution, and the preconcentration factor was 140. The maximum capacity of the sorbent was 2.4 mg Pd(II)/g modified organo nanoclay. The influences of the experimental parameters, including sample pH, eluant volume, eluant type, sample volume, and interfering ions, on the recoveries of the palladium ion were investigated. The proposed method was applied to the preconcentration and determination of palladium in different samples.