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In this report we demonstrate the use of Citrus japonica (CJ) leaf extract for the first time as biological liquid to work as capping as well as reducing agent for synthesizing extremely stable silver nanoparticles (AgNPs) from its precursor silver salt. Different parameters such as pH, speed of reaction, silver salt concentrations and leaf extract were optimized for the formation of CJ-AgNPs. CJ-AgNPs were then characterized through techniques like Ultra-violet visible (UV–Vis) spectroscopy, Fourier transform infra-red (FTIR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), Zeta-potential analysis (ZPA) and dynamic light scattering (DLS). As-formed CJ-AgNPs were verified as highly sensitive, extremely selective, stable, economical, eco-friendly and rapidly responsive colorimetric sensor for Hg2+ detection based on color change in solution from yellow to brownish. The dynamic range of developed sensor worked linearly in the range of 0.3–7.3 µM with R2 value of 0.999 and limit of (LOD) and limit of quantification (LOQ) as 0.09 µM and 0.30 µM respectively. The sensor demonstrated negligible interference under the influence of ions like Mg2+, Zn2+, Cu2+, Co2+, Pb2+, Cd2+ and Fe2+ and corresponding anions. The developed sensor was successfully applied to detect Hg2+ at low level in some real water samples.

In this study, we prepare synthetic arsenic-imprinted polymer (As-IP) by simple precipitation polymerization method by using 4-vinyl pyridine and 2-hydroxyethyl methacrylate as ligand and functional monomer use for the selective elimination of arsenic (As3+) from the aqueous environment. To achieve maximum sorption capacity several factors, i.e., pH, agitation time, shaking speed and sorbent dose were optimized. This prepared polymer was characterized by using SEM, EDX and FT-IR. Adsorption isotherm and kinetic data of As3+ follow the Langmuir isotherm and pseudo-second-order kinetic model. The maximum sorption capacity of As-IP is 106.3 mg/g. The limit of detection and limit of quantification were found to be 0.87 and 2.9 µg/L, respectivley. The relative selectivity factors of As-IP as compared to NIP for As3+/Cr3+, As3+/Al3+, As3+/Ni2+, As3+/Cu2+, As3+/NO3−, As3+/PO43− and As3+/SO42− were 1.445, 1.779, 1.469, 1.168, 1.481, 1.802 and 2.367, respectively. The adsorption efficiency of As3+ ions by using As-IP from real water samples was approximately 99% which shows that As-IP has good sorption capability and highly selective for the extraction of arsenic ions. Graphical representation of As-IP

Herein we demonstrate a simplistic microwave assisted chemical precipitation approach regarding the synthesis of zinc oxide nanoparticles. As-prepared ZnO nanoparticles (NPs) were characterized by UV–visible spectroscopy, Fourier transform infra-red spectroscopy, atomic force microscopy and x-ray diffractometry and scrutinized as photo-catalysts for degradation of 4-chlorophenol (4-CP) under sunlight. The study substantiated that 98.5% of 4-CP was degraded within 20 min in the absence of initiator like H2O2 which reflects an outstanding prospective use for ZnO NPs as photo-catalysts. The nanocatalysts were recycled four times and still showed catalytic efficiency up to 95.5% for degradation of 4-CP in the specified 20 min.

Three different gas chromatographic detection techniques were applied for the determination of deoxynivalenol (DON) present in poultry feed samples. Extraction and cleanup procedures were kept the same for GC–FID, GC–ECD and GC–MS methods. Although all three GC methods provided good and comparable results, but more attention was focused on GC–FID due to its lower cost and easy availability in many laboratories. Therefore, a short 15 m DB-1 short column was introduced for the determination of DON in poultry feed to reduce the time of analysis and initial cost of column. An inter-laboratory study for GC–FID was performed in two laboratories using four naturally DONS-contaminated feed samples and one spiked with standard. The relative standard deviations for repeatability (RSDr) and relative standard deviations for reproducibility (RSDR) of naturally contaminated feed were in the range 5–23 and 11–24 %, respectively. The Horwitz Ratio (HORRAT) was less than 1.0 in each sample. From the spiking test, recovery, RSDr, RSDR and value of HORRAT were 93, 5, 11 and 0.6 %, respectively. For GC–FID method, limit of quantification was found to be 6 μg kg−1. Thus, GC–FID method using 15 m DB-1 capillary column is sensitive and validated analytical method for the determination of DON for poultry feed.

Ethyl chloroformate was used as a derivatizing reagent to develop a simple and sensitive gas chromatographic procedure for the determination of tranexamic acid. Analysis was performed on an HP-5 column (30 m × 0.32 mm i.d.) coupled with mass spectrometric detection. Linear response was obtained from 60 to 500 pg with a limit of detection of 20 pg tranexamic acid injected onto the column. Aminocaproic acid was used as an internal standard. Tranexamic acid was determined in pharmaceutical preparations and blood samples after therapy with the drug. Appoximately 2.0 μg mL−1 was found in blood samples. Relative standard deviation for analysis was within 0.1–0.4% (n = 3). Recovery of tranexamic acid added to deprotenized serum was 99.6% with an RSD of 1.2–1.6% (n = 3). Pharmaceutical additives and amino acids, if also present, did not affect the determination.

Sensitive cathodic stripping voltammetric methods have been developed for two quinolone antibacterial drugs, pipemidic acid (PIP) and ofloxacin (OFL) using hanging mercury drop electrode as working electrode vs. Ag/AgCl reference electrode. The methods were developed for the determination of drugs individually as well as simultaneously. 0.1 M and 0.01 M hydrochloric acid was used as medium for PIP and OFL, respectively, 0.1 M potassium chloride was used as base electrolyte. Reduction waves were observed for PIP within −700 mV to −800 mV and for OFL within −1100 mV to −1200 mV. Linear calibration ranges for PIP and OFL were observed within 10–100 μg ml−1 with detection limits of 50 ng ml−1 and 1 μg ml−1, respectively. Relative standard deviations (RSD) for the analysis of 10 gµg ml−1 of PIP and OFL (n = 6) were 0.5% and 1.4%, respectively. The presence of glucose, lactose, sorbitol, gum arabic, starch, magnesium stearate, methylparaben and propylparaben did not affect the determinations of both PIP and OFL. The methods were used for the analysis of pharmaceutical preparations and the results indicated relative deviation of 0.5–5.5% from labeled values with RSD within 0.49–2.5%. PIP and OFL could also be determined simultaneously, and were determined from spiked human urine.

Groundwater samples were collected from various localities of Mithi sub-district of the Thar Desert of Pakistan and analysed for fluoride ion along with other chemical parameters. The area is mainly covered by sand dunes and kaolin/granite at variable depths. Results showed that collected water samples were severely contaminated by the presence of fluoride ion and most of the samples have higher concentration than prescribed WHO standards (1.5 mg/l) for drinking water. Fluoride ion concentrations ranged between 0.09 and 11.63 mg/l with mean and median values of 3.64 and 3.44 mg/l, respectively, in this area whereas, distribution pattern showed high concentrations in the vicinity of Islamkot and Mithi towns. The content of F− has also been correlated with other major ions found in the groundwater of the study area. The positive correlation of F− with Na+ and HCO3 − showed that the water with high Na+ and HCO3 − stabilizes F− ions in the groundwater of the Thar Desert. The pH versus F− plots signifies high fluoride concentration at higher pH values, implying that alkaline environment favours the replacement of exchangeable OH− with F− in the groundwater of Mithi area. The saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the groundwater samples showed that most of the samples are oversaturated with respect to calcite whereas majority of samples have been found under saturated with respect to fluorite. The log TDS and Na/Na+Ca ratio reflected supremacy of weathering of rocks, which promotes the availability of fluoride ions in the groundwater. Piper diagram has been used to classify the hydrofacies. In the cation triangle, all samples are Na-type, while the anion triangle reflects major dominance of Cl-type with a minor influence of HCO3 − and SO4 −.

A simple, inexpensive method based on solid-phase extraction (SPE) on sawdust from Cedrus deodera has been developed for speciation of Cr(III) and Cr(VI) in environmental water samples. Because different exchange capacities were observed for the two forms of chromium at different pH-Cr(III) was selectively retained at pH 3 to 4 whereas Cr(VI) was retained at pH 1-complete separation of the two forms of chromium is possible. Retained species were eluted with 2.5 mL 0.1 mol L(-1) HCl and 0.1 mol L(-1) NaOH. Detection limits of 0.05 and 0.04 microg mL(-1) were achieved for Cr(III) and Cr(VI), respectively, with enrichment factors of 100 and 80. Recovery was quantitative using 250 mL sample volume for Cr(III) and 200 mL for Cr(VI). Different kinetic and thermodynamic properties that affect sorption of the chromium species on the sawdust were also determined. Metal ion concentration was measured as the Cr(VI)-diphenylcarbazide complex by UV-visible spectroscopy. The method was successfully applied for speciation of chromium in environmental and industrial water samples.

Capillary GC of metal chelates of diethyl dithiocarbamate (DDTC) was examined on a methylsilicone DB-1 column, (25 meter, 0.2 mm. i.d) with a film thickness of 0.25 μm. Elution was carried out at the initial column temperature of 180°C and programmed at 5°C min−1 to 260°C. Detection was by FID or ECD. Symmetrical peaks with base line separation were obtained with the metal chelates of copper(II), nickel(II), cobalt(III), manganese(II) and chromium(III). The ECD gave better sensitivity than the FID with a linear calibration range of 5–50 μg mL−1 and detection limits 2.0–6.0 μg mL−1, corresponding to 111–333 pg of metal ion reaching the detector. The method was applied to the determination of metal ions in water and pharmaceutical preparations with a coefficient of variation (CV) within 4.0%. When compared with a standard flame AAS method the results revealed no significant difference.

The genus Abies family Pinaceae consists of 51 species ranged mainly in temperate and boreal regions of the northern hemisphere, chiefly in mountainous regions [1]. The literature data on phytochemical and biological investigations of the genus of Abies revealed that up to now, 277 compounds were isolated from 19 plants of Abies species. The chemical constituents are mostly terpenoids, flavonoids, and lignans, together with minor constituents of phenols, steroids, and others. The crude extracts and metabolites have been found to possess various bioactivities, including insect juvenile hormone, antitumor, antimicrobial, antiulcerogenic, antiinflammatory, antihypertensive, antitussive, and CNS (central nervous system) activities [2]. Abies pindrow Royle, commonly known as west Himalayan fir, is a large evergreen tree growing up to 40–60 m tall with a trunk diameter of up to 2–2.5 m. It has a conical crown with level branches. In Pakistan, Abies pindrow Royle, known as partal or palundar, is widely distributed at elevations between 2000 and 3000 m throughout the western Himalayas from Afghanistan to Nepal [3]. Pindrow species of Abies is regarded as carminative, stomachic, astringent, expectorant, tonic, antispasmodic, and antiperiodic [4]. Phytochemical studies of the species resulted in the isolation of glucopyranoside, hydroxyflavanone, chalcone glycoside, bioflavonoids, flavonoids and pindrolactone [5], and pentacyclic triterpenoids [6]. Different extracts from the leaves of Abies pindrow Royle exhibited anti-inflammatory, analgesic, and hypnotic activities in rats, attenuated swim stress in mice, and produced hypotension in dogs. Abies pindrow Royle leaves also have an antiulcerogenic effect on the cold-restrained gastric ulcer model in rats [5]. A review of the literature revealed that no hydrocarbons have yet been reported from Abies pindrow Royle. We have previously reported the fatty acid composition of the ethanol extract of the leaves of Abies pindrow Royle. A total of 11 fatty acids, including eight saturated and three unsaturated, was characterized [4]. The present investigation of aerial part (leaves) of Abies pindrow Royle describes the occurrence of long chain hydrocarbons. The presence of these hydrocarbons is detected by GC-MS and supported by FTIR. A careful look at the fragmentation pattern in the mass spectral data reveals the presence of saturated and unsaturated hydrocarbons. These hydrocarbons have been reported for the first time from Abies pindrow Royle. The GC-MS of the hexane fraction revealed the presence of tricosane, eicosane, heneicosane, docosane, tetracosane, nonadecane, octadecane, 1-docosene, 1-octadecene, heptadecane, and 2,6,10,14-tetramethylhexadecane. The identity of these common hydrocarbons was made by comparison of these peaks with the standards by gas chromatography and confirmed by comparison of the fragmentation pattern with those of standard mass spectrum. FTIR analysis supported the structures of these hydrocarbons. The FTIR spectrum exhibits the diagnostic peaks relating to C-H stretching at 2956 cm–1, 2923 cm–1, and 2852 cm–1, C-H bending (scissoring) at 1465 cm–1, C-H methyl rocking at 1378 cm–1, and long-chain methyl rocking at 722.9 cm–1. These peaks verify the required data regarding the hydrocarbons. The GC-MS study of major peaks revealed the presence of straight-chain saturated hydrocarbons. It showed the presence of 11 compounds. The GC-MS pattern showed 11 major peaks along with small peaks. All major peaks were detected as hydrocarbons by GC-MS at different retention times.

A capillary gas chromatographic method is described for the determination of cisplatin based on the complexation of platinum(II) with bis(isovalerylacetone) ethylenediimine (H2IVA2en) and extraction in chloroform. The chromatography was carried out on a BP1 or a BP5 column with an FID. Copper(II), nickel (II) and palladium(II) separated completely and did not affect the determination of platinum(II). The method was applied of the determination of cisplatin in a pharmaceutical preparation and blood samples of cancer patients after infusion of cisplatin. The amounts of cisplatin in blood were found to be within 246–283 ng mL−1 with a C.V. of 2.35–4.26%.