Snake venoms are complex mixtures of proteins and peptides that play vital roles in the survival of venomous snakes. As with their diverse pharmacological activities, snake venoms can be highly variable, hence the importance of understanding the compositional details of different snake venoms. However, profiling venom protein mixtures is challenging, in particular when dealing with the diversity of protein subtypes and their abundances. Here we described an optimized strategy combining a protein decomplexation method with in-solution trypsin digestion and mass spectrometry of snake venom proteins. The approach involves the integrated use of C18 reverse-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and nano-electrospray ionization tandem mass spectrometry (nano-ESI-LC-MS/MS).
This study describes a dispersive liquid-liquid microextraction combined with dispersive solid-phase extraction method based on phenyl-functionalized magnetic sorbent for the preconcentration of polycyclic aromatic hydrocarbons from environmental water, sugarcane juice, and tea samples prior to gas chromatography with mass spectrometry analysis. Several important parameters affecting the extraction efficiency were investigated thoroughly, including the mass of sorbent, type and volume of extraction solvent, extraction time, type of desorption solvent, desorption time, type and amount of salt-induced demulsifier, and sample volume. Under the optimized extraction and gas chromatography-mass spectrometric conditions, the method revealed good linearity (10-100000 ng/L) with coefficient of determination (R2 ) of ≥0.9951, low limits of detection (3-16 ng/L), high enrichment factors (61-239), and satisfactory analyte recoveries (86.3-109.1%) with the relative standard deviations
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
With varied, brightly patterned wings, butterflies have been the focus of much work on the evolution and development of phenotypic novelty. However, the chemical structures of wing pigments from few butterfly species have been identified. We characterized the orange wing pigments of female Elymnias hypermnestra butterflies (Lepidoptera: Nymphalidae: Satyrinae) from two Southeast Asian populations. This species is a sexually dimorphic Batesian mimic of several model species. Females are polymorphic: in some populations, females are dark, resemble conspecific males, and mimic Euploea spp. In other populations, females differ from males and mimic orange Danaus spp. Using LC-MS/MS, we identified nine ommochrome pigments: six from a population in Chiang Mai, Thailand, and five compounds from a population in Bali, Indonesia. Two ommochromes were found in both populations, and only two of the nine compounds have been previously reported. The sexually dimorphic Thai and Balinese populations are separated spatially by monomorphic populations in peninsular Malaysia, Singapore, and Sumatra, suggesting independent evolution of mimetic female wing pigments in these disjunct populations. These results indicate that other butterfly wing pigments remain to be discovered.
This study investigated distributions, composition patterns, sources and potential toxicity of polycyclic aromatic hydrocarbon (PAHs) pollution in surface sediments from the Kim Kim River and Segget River, Peninsular Malaysia. The samples were extracted using Soxhlet extraction, purified using two-step silica gel column chromatography and then analysed by gas chromatography mass spectrometry (GC-MS). The total PAH concentrations ranged from 95.17 to 361.24 ng g-1 dry weight (dw) and 330.09 to 552.76 ng g-1 dw in surface sediments from the Kim Kim and Segget Rivers, respectively. Source type identification using PAH molecular indices and hierarchical cluster analysis (HCA) indicated that PAHs were mostly of pyrogenic origin, while in some stations petrogenic sources had a significant portion. A PAH toxicity assessment using sediment quality guidelines (SQGs), mean effect range-median quotient (M-ERM-Q), benzo[a]pyrene (BaP) equivalent concentration and BaP toxicity equivalent quotient (TEQcarc) indicated low probability of toxicity for both the Kim Kim and Segget Rivers. Moreover, the human health risk assessment applying Cancer Riskingestion and Cancer Riskdermal indicated that probabilistic health risk to humans via ingestion and dermal pathways from sediments of the Kim Kim and Segget Rivers can be categorised as low-to-moderate risk.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Wax apple is one of the underutilized fruits that is considered a good source of fibers, vitamins, minerals as well as antioxidants. In this study, a comparative analysis of the developments of wax fruit ripening at the proteomic and metabolomic level was reported. 2D electrophoresis coupled with MALDI-TOF/TOF was used to compare the proteome profile from three developmental stages named immature, young, and mature fruits. In general, the protein expression profile and the identified proteins function were discussed for their potential roles in fruit physiological development and ripening processes. The metabolomic investigation was also performed on the same samples using quadrupole LC-MS (LC-QTOF/MS). Roles of some of the differentially expressed proteins and metabolites are discussed in relation to wax apple ripening during the development. This is the first study investigating the changes in the proteins and metabolites in wax apple at different developmental stages. The information obtained from this research will be helpful in developing biomarkers for breeders and help the plant researchers to avoid wax apple cultivation problems such as fruit cracking.
Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
There are various approaches to enhancing the catalytic properties of TiO₂, including modifying its morphology by altering the surface reactivity and surface area of the catalyst. In this study, the primary aim is to enhance the photocatalytic activity by changing the TiO₂ nanotubes' architecture. The highly ordered infrastructure is favorable for a better charge carrier transfer. It is well known that anodization affects TiO₂ nanotubes' structure by increasing the anodization duration which in turn influence the photocatalytic activity. The characterizations were conducted by FE-SEM (fiend emission scanning electron microscopy), XRD (X-ray diffraction), RAMAN (Raman spectroscopy), EDX (Energy dispersive X-ray spectroscopy), UV-Vis (Ultraviolet visible spectroscopy) and LCMS/MS/MS (liquid chromatography mass spectroscopy). We found that the morphological structure is affected by the anodization duration according to FE-SEM. The photocatalytic degradation shows a photodegradation rate of k = 0.0104 min-1. It is also found that a mineralization of Simazine by our prepared TiO₂ nanotubes leads to the formation of cyanuric acid. We propose three Simazine photodegradation pathways with several intermediates identified.
The capsicum seed core and cabbage outer leaves are common wastes generated in the vegetable processing industry. We explored the in vitro health-promoting activity of these waste products for valorization. Freeze-dried and pulverized cabbage wastes had a high bile acid binding capacity and the capsicum wastes inhibited glucose dialysis more effectively. Methanolic extracts prepared with conventional solvent extraction and ultrasound-assisted extraction were analyzed to determine their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, in vitro α-amylase inhibitory, in vitro lipase inhibitory, and prebiotic activity. Crude extracts of cabbage and capsicum wastes were screened using GC-MS analysis. The cabbage waste extracts showed high antioxidant activities but did not inhibit α-amylase. The capsicum waste extracts inhibited both lipase and α-amylase activities and supported the growth of the probiotic bacterium, Lactobacilli brevis. Volatile compounds of the vegetables consisted mainly of phenols and fatty acid esters. In all assays except the α-amylase inhibition assay, the extracts prepared with ultrasound-assisted solvent extraction showed higher activity than those prepared using the conventional method. The capsicum seed core and cabbage outer leaves are potential sources of phytochemicals and antioxidant fibers. Capsicum waste extract supported probiotic bacterial growth without a lag phase. These waste products may be processed into high-value functional ingredients.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Rice fungal pathogens, responsible for severe rice yield loss and biotoxin contamination, cause increasing concerns on environmental safety and public health. In the paddy environment, we observed that the asymptomatic rice phyllosphere microenvironment was dominated by an indigenous fungus, Aspergillus cvjetkovicii, which positively correlated with alleviated incidence of Magnaporthe oryzae, one of the most aggressive plant pathogens. Through the comparative metabolic profiling for the rice phyllosphere microenvironment, two metabolites were assigned as exclusively enriched metabolic markers in the asymptomatic phyllosphere and increased remarkably in a population-dependent manner with A. cvjetkovicii. These two metabolites evidenced to be produced by A. cvjetkovicii in either a phyllosphere microenvironment or artificial media were purified and identified as 2(3H)-benzofuranone and azulene, respectively, by gas chromatography coupled to triple quadrupole mass spectrometry and nuclear magnetic resonance analyses. Combining with bioassay analysis in vivo and in vitro, we found that 2(3H)-benzofuranone and azulene exerted dissimilar actions at the stage of infection-related development of M. oryzae. A. cvjetkovicii produced 2(3H)-benzofuranone at the early stage to suppress MoPer1 gene expression, leading to inhibited mycelial growth, while azulene produced lately was involved in blocking of appressorium formation by downregulation of MgRac1. More profoundly, the microenvironmental interplay dominated by A. cvjetkovicii significantly blocked M. oryzae epidemics in the paddy environment from 54.7 to 68.5% (p < 0.05). Our study first demonstrated implication of the microenvironmental interplay dominated by indigenous and beneficial fungus to ecological balance and safety of the paddy environment.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
A novel mass spectrometry detection technique based on a multi-period and multi- experiment (MRM-EPI-MRM3) with library matching in a single run for fast and rapid screening and identification of amphetamine type stimulants (ATS) related drugs in whole blood, urine and dried blood stain was developed and validated. The ATS-related drugs analyzed in this study include ephedrine, pseudoephedrine, amphetamine, methamphetamine, MDMA (3,4-Methylenedioxymethamphetamine), MDA (3,4-Methylenedioxyamphetamine), MDEA (3,4-Methylenedioxy-N-ethylamphetamine) and phentermine. The relative standard deviation for inter and intraday was less than 15% while recoveries ranged from 80% to 120% for all three matrices, i.e., whole blood, urine and dried blood stain. All compounds gave library matching percentage of more than 85% based on the purity. This method was proven to be simple and robust, and provide high confident results complemented with library matching confirmation.
The biosynthesis of nanoparticles has been proposed as a cost-effective and environmental friendly alternative to chemical and physical methods. The present study was aimed to characterise Catharanthus roseus (C. roseus)-silver nanoparticles (AgNPs) using a standardised C. roseus aqueous extract. Methods: The standardisation was performed by using Liquid Chromatography/Time-of-Flight ion trap Mass Spectrometry. An optimised C. roseus-AgNPs have been previously synthesised. Further characterisation of C. roseus-AgNPs was evaluated by zeta potential analysis and fourier transform infrared spectroscopy (FTIR). Results: The chromatography analysis has revealed presence of thirteen possible indole alkaloids in C. roseus extract which were lochrovicine, lochnerine, vinleurosine, vindolinine, tabersonine, catharanthine, serpentine, catharosine, vincristine, catharine, ajmalicine, vinleurosine, and vindolicine. Zeta potential analysis exhibited the value at -16.6 mV. FTIR spectrum of C. roseus aqueous extract showed the absorption band at 3210.83 cm-1 (C-H stretch), 2934.11 (C-H bond), 1578.15 (N=O stretch), 1388.76 and 1314.89 (N=O bend), 1119.29 (C-O bond) and 729.94 (C-Cl bond). In comparison, FTIR spectrum of C. roseus-AgNP s showed the absorption band at 2925.01 and 2924.97 (C-H bond), 1622.93 (C-C=C symmetric stretch), 1383.19 and 1384.13 (N-O bend), 1037.92/1038.76/1238.3/1117.2 (C-O bond), 3169.4 (O-H bond), 774.59 and 691.53 (C-Cl bond). Conclusion: The present findings have shown that the C. roseus aqueous extract contains alkaloids that may responsible as reducing and stabilising agents in the synthesis of AgNPs.
A study has been carried out to characterize hydrocarbons emitted from the burning of three tropical wood species. The woods were burned to ember and smoke aerosols emitted were sampled using high volume sampler fitted with a pre-cleaned glass fibre filters. Hydrocarbons were extracted using ultrasonic agitation with dichloromethane-methanol (3:1 v/v) as solvent and the extracts obtained were then fractionated on silica-alumina column. Detection and quantification of aliphatic and polycyclic aromatic hydrocarbons (PAHs) compounds were carried out using GC-MS. The results indicated that the major aliphatic hydrocarbons characterized were straight chain n-alkanes in the range of C12-C35 with Cmax in the range of C27-C33. Rhizophora apiculata and Hevea brasiliensis wood smoke exhibited a weak odd to even carbon number predominance with carbon preference index (CPI) values greater than one whereas Melaleuca cajuputi wood smoke aerosols did not exhibit similar pattern with CPI obtained close to one. The results obtained also indicated that burning of these wood resulted in formation of PAHs compounds in their smoke aerosols with predominance of three to four rings PAHs over the two, five and lesser of six rings PAHs. PAH diagnostic ratios calculated except for Flan/(Flan+Py) and Indeno/(Indeno+BgP) were consistent with the ratios suggested for wood combustion source as reported in literatures. In the case of the latter, two diagnostic ratios, the values were generally lower than the range normally reported for wood combustion.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The phytochemical investigation on the fruit peel of Goniothalamus scortechinii (Selayar Raja Ubat) obtained from Gunung Stong, Kelantan has resulted in the isolation of five compounds namely pinocembrine, altholactone, goniofufurone, goniotriol and goniopypyrone. Their structures were determined by extensive ultra violet (UV), infrared (IR), nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrum (GCMS) analysis.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The seeds of C. cleomifolia (locally known as kacang hantu) collected along Simpang Pulai - Berinchang Road, Cameron Highlands, was defatted with hexane and the resulting oil was analysed for their physico-chemical properties. The percentage yield of the oil was calculated as 5.3%. The acid value (1.2%), iodine value (85), peroxide value (0.6), saponification value (192.0) and unsaponifiable matter (2.3%) were determined to assess the quality of the oil. The physico-chemical characterisation showed that C. cleomifolia seeds oil is unsaturated semi-drying oil, with high saponifi cation and acidic values. The fatty acid composition of C. cleomifolia seed oil was determined by Gas Chromatography and Gas Chromatography-Mass Spectrometry (ToF). The seed oil of C. cleomifolia contained linoleic acid (57.59%) and palmitic acid (5.07%), the most abundant unsaturated and saturated fatty acids, respectively. The polyunsaturated triacylglycerol (TAG) in C. cleomifolia seed oil determined by reverse phase High performance Liquid Chromatography; contained as PLL (18.04%) followed by POL + SLL (11.92%), OOL (7.04%) and PLLn (6.31%). The melting and cooling point of the oil were 16.22°C and -33.54°C, respectively
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Dalam kajian ini, bakteria asid laktik (LAB) serta sebatian aroma ikan pekasam daripada spesies yang berbeza
ditentukan. Persampelan ikan pekasam iaitu tilapia, loma, lampam, sepat dan gelama diperoleh daripada pembekal
Perusahaan Ikan Pekasam Kiah di Kuala Kangsar, Perak. Penentuan spesies LAB dijalankan melalui kaedah pencairan
bersiri, pengkulturan LAB, ujian katalase, ujian pewarnaan spora serta ujian pengesanan Gram bakteria dan morfologi.
Pengesahan spesies LAB dijalankan melalui pengekstrakan asid deoksiribonukleik (DNA), amplifikasi dengan tindak
balas rantaian polimerasi (PCR), analisis elektroforesis gel dan penjujukan DNA. Hasil jujukan DNA yang diperoleh
dibandingkan dengan jujukan dalam pangkalan data GenBank di NCBI menggunakan BLAST. Didapati Lactobacillus
brevis KB290 DNA dan Lactobacillus casei W56 wujud dalam pekasam tilapia, Lactobacillus plantarum 16 dalam
pekasam lampam, Lactobacillus casei BD-II kromosom dan Lactobacillus plantarum WCFS1 dalam pekasam sepat,
Corynebacterium vitaeruminis DSM 20294 dan Streptococcus anginosus C1051 dalam pekasam gelama. Manakala
Staphylococcus carnosus subsp. carnosus TM300 kromosom adalah LAB dominan dalam pekasam loma. Sementara
itu, sebatian aroma ditentukan melalui kaedah pengekstrakan cecair menggunakan pelarut metanol dan heksana.
Pemprofilan sebatian aroma dijalankan dengan kromatografi gas-spektometer jisim (GC-MS). Sebatian aroma dalam
ekstrak metanol dan heksana daripada lima jenis ikan pekasam dibandingkan. Bilangan sebatian aroma yang diekstrak
menggunakan metanol adalah lebih banyak berbanding dengan yang menggunakan heksana. Sebatian aroma yang
paling banyak dikesan adalah daripada pekasam loma. Asid karboksilik merupakan sebatian yang paling dominan
dalam ikan pekasam dan memberi bau hamis serta tengik.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
A comparative analysis of metabolites from different parts of Curcuma aeruginosa, i.e. leaves, stems, adventitious
roots and rhizomes was performed by GC-MS/MS coupled with multivariate statistical analysis. The GC-MS/MS analysis
confirmed the occurrence of 26 metabolites belonged to terpenoids in almost all the samples. The Principal Component
Analysis (PCA) indicated that there was a clear distinction between rhizomes and other plant parts, i.e. stems, leaves,
and adventitious roots that could be explained by relatively higher contents of terpenoids including curzerene, alphafarnesen, furanocoumarin, velleral, germacrone cineole, borneol, beta- and gamma- elemene and methenolone. The
results of Hierarchical Clustering Analyses (HCA) corresponded with the PCA results where many terpenoids found
abundantly high in rhizome were clustered together. This was supported by the Pearson correlation analysis that
showed a significantly good relationship between those terpenoids. The adventitious roots demonstrated the strongest
antioxidant activity as compared to the other plant parts which could be attributed to its highest Total Phenolic
Contents (TPC). Total phenolic contents of all the plant parts were positively correlated with their antioxidant activities
which indicate that phenolic compounds may play a role in the overall antioxidant activities of the plants. The results
of the study highlighted the potential of this underexploited Curcuma species which could serve as a new source of
important phytochemicals and natural antioxidant that could be incorporated in functional foods and nutraceuticals.
In addition, chemical and biological evidence shown in the present work has rationalised the different uses of various
plant parts of C. aeruginosa.
The big challenge for the detection of pharmaceutical residues in water samples is the type of ionization mode in
terms of positive or negative ionization which plays an important role to identify and quantify the analytes using liquid
chromatography/mass spectrometry. An analytical method was applied to analysis of gliclazide (diabetic drug) in surface
water and wastewater from sewage treatment plants and hospitals. The proposed analytical method allows simultaneous
isolation and concentration procedure using solid phase extraction (Oasis HLB) prior to separation using high-performance
liquid chromatography. The detection and confirmation was achieved by applying time-of-flight analyzer. The limits of
quantification were as low as 1.4 ng/L (deionized water), 4 ng/L (surface water), 27 ng/L (hospital influent), 10 ng/L
(hospital effluent), 6 ng/L (sewage treatment plant effluent) and 21 ng/L (sewage treatment plant influent), respectively. On
average, good recoveries of higher than 87% were obtained for gliclazide in the studied samples. The proposed method
successfully determined and quantified gliclazide in surface water and wastewater. The results showed that gliclazide
is a persistent compound in sewage treatment effluents as well as in the recipient rivers. Gliclazide was detected in all
samples and the highest concentration was 130 ng/L in influent of sewage treatment plant.
This study evaluates the effects of subcritical hydrothermal treatment on palm oil mill effluent (POME) and its concomitant formations of solid hydrochar, liquid product and gaseous product. The reactions were carried out at temperatures ranged 493 K-533 K for 2 h. The highest reduction of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were 58.8% and 62.5%, respectively, at 533 K. In addition, the removal of total suspended solids (TSS) achieved up to 99%, with the pH of POME reaching 6 from the initial pH 4. The gas chromatography coupled with mass spectroscopy (GC-MS) analysis showed that the fresh POME contained n-Hexadecanoic acid as the dominant component, which gradually reduced in the liquid product in the reaction with increased temperature, in addition to the attenuation of carboxyl compounds and elevation of phenolic components. The gaseous products contained CO2, CO, H2, and C3 - C6 hydrocarbons. Traces of CH4 were only found at 533 K. CO2 is the dominant species, where the highest of 3.99 vol% per 500 mL working volume of POME recorded at 533 K. The solid hydrochars showed negligible morphological changes across the reaction temperature. The O/C atomic ratio of the hydrochar range from 0.157 to 0.379, while the H/C atomic ratio was in the range from 0.930 to 1.506. With the increase of treatment temperature, the higher heating value (HHV) of the hydrochar improved from 24.624 to 27.513 MJ kg-1. The characteristics of hydrochar make it a fuel source with immense potential. POME decomposed into water-soluble compounds, followed by deoxygenation (dehydration and decarboxylation) in producing hydrochar with lower oxygen content and higher aromatic compounds in the liquid product. Little gaseous hydrocarbons were produced due to subcritical hydrothermal gasification at low temperature.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The purpose of this study was to determine aluminium (Al) concentrations in groundwater used for drinking and cooking and its related health risk among population of 28th Mile Orang Asli village in Jenderam Hilir, Selangor, Malaysia. A total of 100 respondents were recruited, comprising 51 (51.0 %) male and 49 (49.0 %) female residents. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine Al concentration, while the LAMOTTE TRACER ORP PockeTester was used to measure pH levels. Statistical Package for Social Science (SPSS) was used to analyze the data. Results showed that Al concentration ranged from 0.041 - 0.136 mg/L with a mean of 0.136 + SD 0.041 mg/L, hence the values obtained were below the standard value (0.2 mg/L). pH levels ranged from 3.82 to 5.84, with a mean of 4.163 + SD 0.411, which is acidic and below the range permitted by the health authorities. The acidic nature may have an impact on the Al concentration in the water. The Hazard Index (HI) was found to be less than 1, thus there was no health risk of Al exposure in drinking water for the respondents involved. The study area was considered safe from having health risk associated with Al exposure.
Screening for drugs of abused were conducted by using Gas chromatography-Mass spectrometry (GCMS) fitted with capillary column. Urine samples supplied by Centre of Inmigrant Studies, University of Malaya were processed upon arrival and screened for the following drugs. Amphetamines, methamphetamines, aphedrine, hydroxy-amphetamines, ecstasy, benzamphetamines, codeine, morphine, heroine, cocaine and diazepam. The analysis was done using Shimadzu QP5000 Gas chromatograph-mass spectrometer by selected ion monitoring with BPX35 column, 15 m length, 0.32 ID, helium gas as carrier and quadropole mass detector at 1.60 kV electron gain. Analysis were performed using selected ion monitoring (SIM) mode and quantitations were based on area under the curve of individual standards at various concentrations. The method is sensitive to nanogram levels and are able to detect the presence of these drugs in both urine and plasma. From this study (n-100), none of the urine were found positive for the drugs screened. The major problem encountered were adulterated with water based on the clearness and the colour of the urine. Based on this suspicion we would like to suggest that the testing be done on blood samples as this would be more confirmative and quantitative.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry