Steroid hormones in systemic sclerosis: associations with disease characteristics and modifications during scleroderma renal crisis.

OBJECTIVE: The renin-angiotensin-aldosterone system (RAAS) and glucocorticoids (GCs) are involved in vascular remodeling and fibrosis, but have not been extensively studied in systemic sclerosis (SSc). Our aim was to investigate the RAAS and GC hormones in SSc patients. METHODS: Serum levels of renin (dosage and activity), aldosterone and its precursors (DOC, B, 18-OH-DOC, 18-OH-B), and GCs (cortisol, cortisone, 11-deoxycortisol, 18-OH-F) were assessed in 122 SSc patients and 52 healthy controls. After applying stringent inclusion criteria aimed at ensuring accurate hormone assessments (exclusion of interfering drugs, strict sampling conditions), we analyzed RAAS hormones in 61 patients, and GCs in 96 patients. Hormone levels were compared between patients and controls; and associations with disease characteristics were assessed in patients. RESULTS: Regarding RAAS hormones, SSc patients displayed significantly lower aldosterone levels (although within normal range), similar renin levels, and higher B levels than controls. Abnormal RAAS hormone levels were associated with a more severe SSc phenotype (lung and skin fibrosis, heart and pulmonary vascular involvements, inflammation). Regarding GC hormones, SSc patients had higher levels of cortisol, 11-desoxycortisol (precursor) and 18-OH-F (metabolite) but lower levels of cortisone (inactive counterpart) than controls.RAAS hormone levels were assessed in 5 SSc patients before and during scleroderma renal crisis (SRC): concentrations varied considerably between patients, but consistently included normal/increased aldosterone levels and elevated renin levels. CONCLUSION: RAAS and GC hormones are abnormally produced in SSc patients, especially in patients with severe SSc and during SRC. This could suggest a participation of these hormonal systems in SSc pathogenesis.

Semiparametric estimation of cross-covariance functions for multivariate random fields.

The prevalence of spatially referenced multivariate data has impelled researchers to develop procedures for joint modeling of multiple spatial processes. This ordinarily involves modeling marginal and cross-process dependence for any arbitrary pair of locations using a multivariate spatial covariance function. However, building a flexible multivariate spatial covariance function that is nonnegative definite is challenging. Here, we propose a semiparametric approach for multivariate spatial covariance function estimation with approximate Matérn marginals and highly flexible cross-covariance functions via their spectral representations. The flexibility in our cross-covariance function arises due to B-spline-based specification of the underlying coherence functions, which in turn allows us to capture nontrivial cross-spectral features. We then develop a likelihood-based estimation procedure and perform multiple simulation studies to demonstrate the performance of our method, especially on the coherence function estimation. Finally, we analyze particulate matter concentrations (PM2.5 ) and wind speed data over the West-North-Central climatic region of the United States, where we illustrate that our proposed method outperforms the commonly used full bivariate Matérn model and the linear model of coregionalization for spatial prediction.

Proteomic Profiling of Liver and Plasma in Chronic Ethanol Feeding Model of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice.

BACKGROUND: Chronic alcohol abuse, a major risk factor for such diseases as hepatitis and cirrhosis, impairs hepatic alcohol dehydrogenase (ADH; key ethanol [EtOH]-metabolizing enzyme). Therefore, differentially altered hepatic and plasma proteomes were identified in chronic EtOH feeding model of hepatic ADH-deficient (ADH- ) deer mice to understand the metabolic basis of alcoholic liver disease (ALD). METHODS: ADH- deer mice were fed 3.5 g% EtOH via Lieber-DeCarli liquid diet daily for 3 months and histology of the liver assessed. Liver and plasma proteins were separated by 2-dimensional gel electrophoresis. The proteins differentially expressed were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. RESULTS: Histology of the liver showed panlobular steatosis and infiltration of T lymphocytes. Using the criteria of ≥1.5 for fold change (p-value ≤0.05) with expectation value (E ≤10-3 ) and protein score (≥64), 18 proteins in the livers and 5 in the plasma of EtOH-fed mice were differentially expressed and identified. Prolyl 4-hydroxylase, cytochrome b-5, endo A cytokeratin, ATP synthase, heat-shock 70 kD proteins, enoyl CoA hydratase, stress-70 protein, peroxiredoxin 1, and ornithine carbamoyl transferase were up-regulated in the livers. However, carbonic anhydrase 3, mitochondrial ATP synthase, aldolase 2, actin γ, laminin receptor, and carbamoyl phosphate synthase were down-regulated. Contrary to the increased expression of creatine kinase M-type, a decreased expression of serine protease inhibitor A3A precursor, sulfated glycoprotein-2 (clusterin), and apolipoprotein E isoforms were found in the plasma of EtOH group. CONCLUSIONS: Chronic EtOH feeding in ADH- deer mice causes steatosis and infiltration of T lymphocytes in the livers along with increased expression of proteins involved in endoplasmic reticulum (ER) stress, fibrosis, fatty acid ß oxidation and biogenesis, and decreased expression of proteins involved in ATP synthesis, carbohydrate metabolism, in cell regulation and architecture. Reduced expression of various carrier proteins as found in the plasma of EtOH group has a biomarker potential.

Tropospheric Emissions: Monitoring of Pollution (TEMPO).

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (H2CO), glyoxal (C2H2O2), bromine monoxide (BrO), IO (iodine monoxide),water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.

Diversity and activity of sulphur-oxidizing bacteria and sulphate-reducing bacteria in landfill cover soils.

UNLABELLED: Sulphur bioconversion in landfill cover soils, including the metabolism of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB), is one of the important processes affecting H2 S emission from landfills. In this study, two landfills with or without landfill gas collection and utilization system were investigated to characterize the role of biotic and abiotic factors affecting diversity and activity of SOB and SRB in the landfill cover soils. The results revealed that the potential sulphur oxidation rates (SORs) and sulphate reduction rates (SRRs) varied with landfill sites and depths. SOR was significantly correlated with pH and SO4 (2-) , while SRR was significantly related with pH. The populations of both SOB and SRB were low in the acidic landfill cover soils (pH = 4.7-5.37). Cloning and terminal restriction fragment length polymorphism profiles of soxB and dsrB showed that SOB including Halothiobacillus, Thiobacillus, Thiovirga and Bradyrhizobium, and SRB including Desulfobacca, Desulforhabdus and Syntrophobacter dominated in the landfill cover soils, and their distributions were affected mainly by pH value and organic matter contents of soils. SIGNIFICANCE AND IMPACT OF THE STUDY: High diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) presented in the landfill cover soils. Among the physicochemical properties of soils (moisture content, pH, organic materials, SO4 (2-) , acid volatile sulphide and total sulphur), pH was the most important factor affecting the diversity and activity of SOB and SRB in the landfill cover soils. Higher pH of landfill cover soils (i.e. neutral or slight alkaline) was favourable for the growth of SOB and SRB, leading to a rapid bioconversion of sulphur. These findings are helpful to optimize sulphur biotransformation in landfill cover soils and to control odour pollution at landfills.

Enrichment of copper as 1-(2-pyridylazo)-2-naphthol complex by the combination of dispersive liquid-liquid microextraction/flame atomic absorption spectrometry.

A rapid, simple, selective, economical, and sensitive dispersive liquid-liquid microextraction methodology has been established for the preconcentration of copper (Cu) at trace levels. The Cu(II) was complexed with 1-(2-pyridylazo)-2-naphthol; ethanol and carbon tetrachloride were used as disperser and extraction solvents, respectively. To obtain quantitative recovery of Cu(II), the effects of parameters influencing its extraction efficiency and subsequent determinations, i.e., pH, amount of complexing reagent, extraction time, and type and volume of disperser and extraction solvents, were examined. LOD and LOQ were 0.06 and 0.20 microg/L, respectively. The enrichment factor of the proposed method was 60, and the RSD <5%. TMDA 51.3 and TMDA 70 fortified water certified reference materials were analyzed for validation of the procedure. The developed microextraction procedure has been used for the preconcentration of Cu(II) in water samples with acceptable results.

1-(2-Methyl-5-nitro-1H-imidazol-1-yl)acetone.

In the mol-ecule of the title compound, C7H9N3O3, the nitro and carbonyl groups are tilted with respect to the imidazole ring by 9.16 (6) and 65.47 (7)°, respectively. Neighbouring chains are linked via C-H⋯N and C-H⋯O hydrogen bonds forming two-dimensional slab-like networks lying parallel to (01-1).

3,5a,9-Trimethyl-8-(2-phenylhydrazin-1-ylidene)-4,5,5a,9b-tetrahydro-3aH,8H-naphtho[1,2-b]furan-2(3H)-one.

The title compound, C(21)H(24)N(2)O(2), is a phenyl hydrazine derivative of the well known anthelminthic agent α-santonin, which is composed of three fused rings (benzodieneone, cyclo-hexane and γ-lactone). The cyclo-hexa-dienone ring adopts a boat conformation, the cyclo-hexane ring is in a chair conformation and the trans-fused γ-lactone ring adopts a C-envelope conformation. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains along the a axis.

8-[(2-Hy-droxy-phen-yl)imino]-3,5a,9-trimethyl-3a,4,5,5a,8,9b-hexa-hydro-naphtho-[1,2-b]furan-2(3H)-one.

The title compound, C(21)H(23)NO(3), is a phenyl-imine derivative of the well known anthelmintic agent α-santonin. The trans-fused cyclo-hexane and γ-lactone rings of the α-santonin ring system adopt chair and envelope conformations, respectively, whereas the hexa-diene ring is approximately planar [maximum deviation = 0.029 (4) Å] and forms a dihedral angle of 62.30 (11)° with the benzene ring. An intra-molecular O-H⋯N hydrogen bond is observed.

New pyrazolone derivatives, synthesis, characterization, and neuroprotective effect against PTZ- induced neuroinflammation in mice.

Objectives: The study was aimed at synthesis of the new derivatives of the pyrazolone nucleus, and their spectroscopic and pharmacological analysis and evaluation. Materials and Methods: Three series of compounds, with 2-picolinic acid (I a-d), 3-picolinic acid (II a-d), and 4-picolinic acid (III a-d) were synthesized and characterized by FT-IR, 1HNMR, 13C NMR, elemental, and melting points. The new compounds were then evaluated for their anti-oxidant, anti-inflammatory, and anti-epileptic potential. The hind paw edema model was used to screen anti-inflammatory potential, while the anticonvulsant effect was evaluated by employing the acute model of anti-epileptic activity. The in vivo anti-oxidant potential was determined through glutathione (GSH), glutathione-S-transferase (GST), catalase, and lipid peroxidase enzyme (LPO) assays. The expression of key biomarkers involved in inflammation and neuroprotection, including tumor necrotic factors alpha (TNF-α) and phosphorylated nuclear factor kappa B (NF-κB), was detected through enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Results: The tested compounds showed anti-oxidant potential. The selected compounds exhibited good anti-inflammatory potential. The PTZ-induced elevation of these inflammatory mediators and oxidative stress were ameliorated significantly by the selected compound Ic. Results of molecular analysis (ELISA and Western blot analysis) for potent compound Ic showed a prominent inhibitory effect against neuroinflammatory mediators, including TNF-α and NF-κB. Conclusion: It is concluded that the derivative Ic ameliorated PTZ-induced seizures, oxidative stress, and inflammatory cascades by regulating the NF-κB/ TNF-α/ROS pathway.

Zinc and iron determination in serum and urine samples of thyroid patients using cloud point extraction.

A simple and rapid cloud point extraction method was applied for preconcentration of trace quantities of zinc (Zn) and iron (Fe) in biological samples (serum and urine) of thyroid patients prior to determination by flame atomic absorption spectrometry. The metals in serum and urine samples were complexed with 1-(2-thiazolylazo)-2-naphthol and entrapped in the surfactant octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol. For optimum recovery of analytes, the influences of the analytical parameters, including pH and amounts of complexing and surfactant reagents, were investigated. Enrichment factors of 66.4 and 70.2 were obtained for the preconcentration of Zn(II) and Fe(III), respectively. The obtained results showed sufficient recoveries (>98%) for Zn(II) and Fe(III) in certified reference materials (CRMs). The proposed method was applied to the determination of Zn(II) and Fe(III) in biological (serum and urine) samples and CRMs.

Plasma homocysteine in patients of migraine without aura.

BACKGROUND: Few studies have studied the role of homocysteine in migraineurs and have produced conflicting results. The MTHFR C677T genotype has been associated with increased risk of migraine in selected clinical samples. We assessed the association of the MTHFR C677T variant with migraine, the corresponding homocysteine levels and their correlation. METHOD: We studied 27 random adult migraineurs with aura (MWA), migraine without aura (MWOA), and 32 non-migraineurs (controls) from Lahore, Pakistan in this pilot study which is still under progress. RESULTS: We found significant differences in homocysteine levels between various diagnostic groups (K-W test: p=0.005). One-way ANOVA, post-hoc tests revealed significant differences in homocysteine levels between Non-migraineurs, MWA (p=0.002, CI: 1.93 - 9.19) and MWoA (p=0.002, CI: -9.19 - -1.9). We found a significant association between the migraine group and C677T-MTHFR variant mutant allele (C/T) (p=0.039). We did not find a significant association between C677T-MTHFR variant and homocysteine levels. CONCLUSION: In this pilot study, we found plasma homocysteine levels to be significantly associated with MWOA. Additionally, plasma homocysteine levels were lower in MWA than in MWOA. Furthermore, we did not find a relationship between homocysteine levels and the MTHFR variant (SNP rs1801133). Lastly, there may be a relationship between the MTHFR variant (SNP rs1801133) and migraine in this population.

Optimization of ultrasonic-assisted acid extraction of mercury in muscle tissues of fishes using multivariate strategy.

A simple and rapid ultrasound-assisted extraction procedure was developed for the determination of total mercury (Hg) in muscle tissues of freshwater fish species. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of variables, such as presonication time (without ultrasonic stirring), sonication time, ultrasonic bath temperature, nitric acid concentration, hydrochloric acid concentration, and sample mass of muscle tissues. Some variables showed a significant effect on recovery, and they were further optimized by a 2(3) + star central composite design that involved 16 experiments. The validation was carried out by analysis of certified reference material DORM-2 (dog fish muscles); for comparative purposes, an acid digestion induced by microwave energy was used. Cold vapor atomic absorption spectrometry was used for the determination of total Hg. No significant differences were established between the analytical results and the certified values (paired t-test at P > 0.05). The LOD and LOQ of Hg were 0.133 and 0.445 microg/kg, respectively, which demonstrated the high sensitivity of the proposed procedure for the determination of Hg at trace levels. The Hg concentrations in the muscle tissues of 10 freshwater fish species were found in the range of 35.3-67.8 microg/kg on a dried basis, which were within the permissible limit of the World Health Organization.

Development and validation of a liquid chromatography-mass spectrometry method for the determination of 4,5-diazafluoren-9-one.

A new liquid chromatography-mass spectrometry (LC-MS) method is developed and validated for the identification and determination of novel 4,5-diazafluoren-9-one compound. The method employs a Waters XTerra RP-18 column (150 mmx4.6 mm, i.d. 5 microm) with a mobile phase comprised of a (50:50, v/v) mixture of deionized water containing 0.2% acetic acid (solvent A) and methanol (solvent B) at a flow rate of 1 mL/min, at 35 degrees C. The detection is performed with photodiode-array (PDA) set at 210-400 nm and single quadropole mass spectrometer with electrospray ionization (ESI) positive ion mode. The chromatographic separation is achieved in less than 3 min. The linearity is established over the concentration range of 0.1-0.5 mg/mL (r2=1.000). The mean RSD values for intra- and inter-day precision studies are <2%. The recovery of 4,5-diazafluoren-9-one ranged between 99.84 and 99.97%. The limits of detection and quantitation are determined to be 0.58 and 0.1 mg/mL, respectively.

Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach.

When the Deepwater Horizon oil rig blew out in 2010, the immediate threats to productive deep water and estuarial fisheries and the region's fishing and energy economies were obvious. Less immediately obvious, but equally unsettling, were risks to human health posed by potential damage to the regional food web. This paper describes grassroots and regional efforts by the Gulf Coast Health Alliance: health risks related to the Macondo Spill Fishermen's Citizen Science Network project. Using a community-based participatory research approach and a citizen science structure, the multiyear project measured exposure to petrogenic polycyclic aromatic hydrocarbons, researched the toxicity of these polycyclic aromatic hydrocarbon compounds, and communicated project findings and seafood consumption guidelines throughout the region (coastal Louisiana, Mississippi, and Alabama). Description/analysis focuses primarily on the process of building a network of working fishermen and developing group environmental health literacy competencies.

Activin subfamily peptides predict chronological age in humans.

Loss of muscle mass and function are a well-defined aspect of human aging from the 3rd decade of life, which result in reduced independence and increased mortality. The activin family of peptides contains several endocrine factors (activin A, myostatin, growth and differentiation factor 11 [GDF11]) that may play roles in changes in muscle mass and the aging process, however, it may be simplistic to consider aging as a result of a single peptides changes. Thus, we aimed to examine changes in activin family members across a cohort of healthy individuals of various ages, hypothesizing that these would aid predictive models of age and functional measures of age. Healthy participants (n = 88) were recruited and resting metabolic rate, body composition, grip strength, walking speed, and circulating plasma concentrations of myostatin (total and free), activin A, follistatin-like binding protein (FLRG), and GDF11 quantified. Simple regressions between circulating factors and chronological age, grip strength, and walking speed were examined. Multiple stepwise regressions for age, grip strength, and walking speed are also reported. Age negatively correlated with total myostatin (P = 0.032, r2  = 0.053), grip strength positively with activin A (P = 0.046, r2  = 0.048), whereas walking speed showed no simple regression relationships. Stepwise regressions suggested a role of total myostatin and activin A in models of age, whereas GDF11 contributed to the model of grip strength. Here we suggest a role for myostatin, activin A, and GDF11 in normal human aging that mirrors animal studies to date. Further interventional studies are required to elicitate the physiological role of these changes in the normal human aging process, and indeed if offsetting these changes can promote successful aging.

Marker-assisted introgression of three dominant blast resistance genes into an aromatic rice cultivar Mushk Budji.

Modern high yielding rice varieties have replaced most of the traditional cultivars in recent past. Mushk Budji, is one such short grained landrace known for its aroma and exquisite quality, however, is highly susceptible to blast disease that has led to considerable decline in its area. Mushk Budji was crossed to a triple-gene donor line, DHMAS 70Q 164-1b and followed through marker-assisted foreground and background selection in first and second backcross generations that helped to incorporate blast resistance genes Pi54, Pi1 and Pita. Marker-assisted background selection was carried out using 78 SSR and STS markers that helped to reduce linkage drag around the genes Pi54, Pi1 and Pita to 2.74, 4.60 and 2.03 Mb, respectively. The three-gene lines in BC2F2:3 were genotyped using 50 K SNP chip and revealed more than 92% genome similarity to the RP. 2-D gel assay detected differentially expressing 171 protein spots among a set of backcross derived lines, of which 38 spots showing match score of 4 helped us to calculate the proteome recovery. MALDI-TOF analysis helped to detect four significant proteins that were linked to quality and disease resistance. The improved lines expressed resistance to blast under artificial and natural field conditions.

Proteins Differentially Expressed in the Pancreas of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice Fed Ethanol For 3 Months.

OBJECTIVES: The aim of this study was to identify differentially expressed proteins in the pancreatic tissue of hepatic alcohol dehydrogenase-deficient deer mice fed ethanol to understand metabolic basis and mechanism of alcoholic chronic pancreatitis. METHODS: Mice were fed liquid diet containing 3.5 g% ethanol daily for 3 months, and differentially expressed pancreatic proteins were identified by protein separation using 2-dimensional gel electrophoresis and identification by mass spectrometry. RESULTS: Nineteen differentially expressed proteins were identified by applying criteria established for protein identification in proteomics. An increased abundance was found for ribosome-binding protein 1, 60S ribosomal protein L31-like isoform 1, histone 4, calcium, and adenosine triphosphate (ATP) binding proteins and the proteins involved in antiapoptotic processes and endoplasmic reticulum function, stress, and/or homeostasis. Low abundance was found for endoA cytokeratin, 40S ribosomal protein SA, amylase 2b isoform precursor, serum albumin, and ATP synthase subunit ß and the proteins involved in cell motility, structure, and conformation. CONCLUSIONS: Chronic ethanol feeding in alcohol dehydrogenase-deficient deer mice differentially expresses pancreatic functional and structural proteins, which can be used to develop biomarker(s) of alcoholic chronic pancreatitis, particularly amylase 2b precursor, and 60 kDa heat shock protein and those involved in ATP synthesis and blood osmotic pressure.

How Do Internal and External CSR Affect Employees' Organizational Identification? A Perspective from the Group Engagement Model.

The literature examines the impact of firms' corporate social responsibility (CSR) activities on employees' organizational identification without considering that such activities tend to have different targets. This study explores how perceived external CSR (efforts directed toward external stakeholders) and perceived internal CSR (efforts directed toward employees) activities influence employees' organizational identification. In so doing, it examines the alternative underlying mechanisms through which perceived external and internal CSR activities build employees' identification. Applying the taxonomy prescribed by the group engagement model, the study argues that the effects of perceived external and internal CSR flow through two competing mechanisms: perceived external prestige and perceived internal respect, respectively. Further, it is suggested that calling orientation (how employees see their work contributions) moderates the effects induced by these alternative forms of CSR. The model draws on survey data collected from a sample of 414 employees across five large multinationals in Pakistan. The results obtained using structural equation modeling support these hypotheses, reinforcing the notion that internal and external CSR operate through different mediating mechanisms and more interestingly employees' calling orientation moderates these relationships to a significant degree. Theoretical contributions and practical implications of results are discussed in detail.

Method development and validation for the GC-FID assay of p-cymene in tea tree oil formulation.

This paper describes the development and validation of an isothermal gas chromatography-flame ionisation detection (GC-FID) method for the assay of pure tea tree oil. The chromatographic conditions of the method employ a 5% carbowax packed column (20 m x 0.25 mm), isothermal elution with hydrogen at a column flow of 36 ml/min, injector and detector temperature at 220 degrees C and oven temperature at 100 degrees C, and a 1.5 microl injection volume. Samples and standard were diluted in hexane. The calibration curve for p-cymene was linear (r2=0.9995) from 20 to 120% range of the analytical concentration of 100 microg/ml. The precision of this method was calculated as the relative standard deviation (R.S.D.) was 0.66% (n=6). The R.S.D. for intermediate precision study was 0.13 and recovery of the p-cymene ranged between 93.39 and 97.86%. The limits of detection and quantitation were determined to be 2.08 and 10.39 ng/ml, respectively.