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The phytoremediation is a significant natural clean-up process for removal of heavy metals from wetland saline soils (WS) for the sustainable environmental pollution control. Therefore, the phytoremediation potential of Typha domingensis(southern cattail) and Phragmitesaustralis(common reed) has been evaluated for absorption and accumulation of salts and heavy metals growing at two sites of WS samples coded as BS1and BS2(“BS” the soil that is not adjoining to root of plants) in Hyderabad Sindh, Pakistan. The three parts (root, stems, and leaves) of both Plants were obtained from several of locations oxidized the matrices of each part of plants and the corresponding soil samples using acid mixture. A variety of techniques were used to identify the metals by atomic absorption spectrometry. The average values of heavy metals, Co, Cd, Cr, Cu, Pb, and Zn in BS1and BS2were found to be (8.53, 14.4, 8.88, 64.3, 13.3, and 142) and (12.4, 18.2, 13.6, 89.4, 14.4, and 124) µg/g, respectively. The data of bioconcentration (BCF) and translocation factors (TF) of the research showed that the studied halophytes showed a high accumulation potential (> 1) for heavy metals from WS. The metal content in plants and rhizospheric soil have a strong relationship (p< 0.01). The screening data based on classical methods and GC–MS indicated that the studied phyto extractants have many phytochemicals. These phytochemicals may have the capability to accumulate heavy metals from contaminated soils. The roots and their rhizospheric soil (RS1and RS2) have a highly significant relationship of accumulation potential with the selected heavy metals (RS is soil adjoining to roots of plants) (p< 0.01). These halophytes are able to remove heavy metals directly from salty metal-contaminated soil in wetland environments.

Solid-phase extraction (SPE) has attracted the attention of scientists because it can increase the selectivity and sensitivity measurements of analytes. Therefore, this study is designed to synthesise magnesium oxide nanoparticles (D-MgO-NPs) by an eco-friendly method using biogenic sources Duranta erectafollowed by fabricating its chitosan-based polymeric composite (D-MgO-NC) for the SPE of heavy metals (HMs), i.e., arsenic (As), cadmium (Cd), and lead (Pb) from drinking water. Various analytical techniques were used for the surface characterization of D-MgO-NPs and D-MgO-NC. FTIR findings confirmed the formation of D-MgO-NC based on MgO association with the –OH/–NH2of the chitosan. D-MgO-NC showed the smallest size of particles with rough surface morphology, followed by the crystalline cubic structure of MgO in its nanoparticle and composites. The synthesised D-MgO-NC was used as an adsorbent for the SPE of HMs from contaminated water, followed by their detection by atomic absorption spectrometry. Various experimental parameters, including pH, flow rate, the concentration of HMs, eluent composition, and volume, were optimised for the preconcentration of HMs. The limits of detection for As, Cd, and Pb of the proposed D-MgO-NC-based SPE method were found to be 0.008, 0.006, and 0.012 μm L−1, respectively. The proposed method has an enrichment factor and relative standard deviation of >200 and <5.0%, respectively. The synthesised D-MgO-NC-based SPE method was successfully applied for the quantitative detection of As, Cd, and Pb in groundwater samples, which were found in the range of 18.3 to 15.2, 3.20 to 2.49, and 8.20 to 6.40 μg L−1, respectively.

Rapid and environmentally friendly ultrasound-assisted dispersive liquid–liquid microextraction (US-DLLμE) and vortex assisted-emulsification liquid–liquid microextraction (VA-ELLμE) methods are proposed for the speciation of selenium in domestic and mineral water samples. A deep eutectic solvent (DES) prepared with different ratios of choline chloride and phenol is used as an extractant for hydrophobic tetravalent Se complexed with diethyldithiocarbamate in different water samples. The total inorganic Se species levels in water samples were determined viareducing Se(vi) to Se(iv), using sodium thiosulphate as a reducing agent. The total Se levels in formula milk and cereal samples were determined after microwave acid digestion. The different heating steps in GFAAS were also optimized. The analytical parameters for US-DLLμE and VA-ELLμE, including pH, the volume of complexing agent, the ultrasound and vortex mixing shaking times, and the volume and composition of the deep eutectic solvent, were optimized. The accuracies of both methods were confirmed based on the analysis of a certified reference material (CRM) BCR 189 (wholemeal flour). The enhancement factor (EF) and limit of detection (LOD) for Se(iv) viaUS-DLLμE were found to be 90.8 and 0.029 μg L−1, respectively, whereas an EF of 81.8 and LOD of 0.036 μg L−1were obtained viaVA-ELLμE. The % relative standard deviation (%RSD) values obtained based on the analysis of six replicate standards under the optimized conditions for US-DLLμE and VA-ELLμE were found to be 4.2 and 5.8%, respectively. The optimized methods were applied to different drinking water samples, and acid-digested milk formula and baby cereal food samples.

The purpose of the current study was to determine the contents of macro and micro minerals (Na, K, Ca, Mg, Cu, Cr, Fe, Mn, Zn) in the twenty-six common spices and estimate of their daily intake by the consumption of common spices. The mineral dissolution from common spices has been done by using acid digestion method and quantified by flame and graphite furnace atomic absorption spectrophotometer. The accuracy and precision of the acid digestion for plant materials have been verified successfully by using the certified reference materials (BCR-100) of Beech leave and (BCR-189) of wholemeal flour. The mineral concentrations in common spices were within safe limits recommended by WHO for minerals in the medicinal plants. However, the contents of Na, K, Ca and Mg were significantly higher in all the spices (p < 0.05). The estimated daily intakes of each mineral in common spices were within the recommended dietary allowance and tolerable upper levels, established by the food and nutrition board, USA.

AbstractIn the current study, we monitored the potentially toxic level of lead (Pb), aluminum (Al), cadmium (Cd) and other physicochemical parameters in different types of drinking water samples of district Jamshoro. Moreover, the objective of this research was the possible risk assessment of hazardous metals level in different types of drinking water used in the local population. The concentrations of toxic metals in water samples of different origin were analyzed using atomic absorption spectrometry. It was observed that the levels of Al, Cd and Pb in lake and ground water elevated as compared to the WHO recommended permissible level. Concentrations of toxic metals in lake and ground water were considerably elevated (p<0.001) as compared to domestic treated water. Based on concentrations of toxic metals; chronic daily intake (CDI) and hazard quotient (HQ) were calculated as factors for health risk assessment. CDI and HQ for lake and ground water revealed that water is unsafe for human activities while the domestic treated water has lower CDI and HQ values. Furthermore, it was also exposed through results obtained with cluster analysis (CA) and principal component analysis (PCA) that geogenic as well as anthropogenic actions is the major contamination cause in understudy area.

A novel switchable hydrophobic–hydrophilic transition dispersive solid–liquid microextraction (SHT-DSLME) method has been used for the first time as a dispersive/extractive method for the removal of total selenium from real samples. Tetraethylenepentamine modified multi-walled carbon nanotubes (MWCNTs-TEPA) were synthesized and employed as an adsorbent for the removal and analysis of total inorganic selenium by SHT-DSLME coupled with graphite furnace atomic absorption spectrometry (GFAAS). In this study, the hydrophobic–hydrophilic transition of MWCNTs-TEPA was achieved by exposing them to a green, inexpensive, non-hazardous and non-accumulating antisolvent trigger: CO2. The switching phenomena of functionalized MWCNTs from hydrophobic to hydrophilic were confirmed using FTIR spectrophotometry and SEM measurements. Under optimized experimental conditions, the enhancement factor (EF) and limit of detection (LOD) were found to be 72 and 0.015 μg L−1, respectively for selenium. Validation of the developed method was carried out by selenium determination using water for trace elements (TM-28.3) as a certified reference material and the results were found to be in good agreement with the certified values. The proposed novel method was then successfully applied for the determination of selenium in real water samples.

A new, innovative and green switchable dispersive liquid–liquid microextraction (SDLLME) method has been introduced as a preconcentration tool for the removal of the toxic metal lead (Pb) in fresh and waste water samples prior to determination with flame atomic absorption spectrometry. We developed a switchable polarity solvent (SPS) system, based on 1,8-diazabicyclo[5.4.0]undec-7-ene and decanol, which was reversibly switched on and off from heterogeneous biphasic nonpolar hydrophobic phase to homogeneous monophasic polar hydrophilic phase in an aqueous medium through exposure to an anti-solvent trigger (CO2) for a specific interval of time (1–10 min). Then, an SPS of polar microemulsions was switched on from a polar phase through bubbling CO2followed by switching off to a nonpolar phase by heating in the range of 40–70 °C in the presence of N2gas. The switching phenomenon of SPS from low polarity to high polarity was confirmed by FTIR spectrophotometry and conductivity measurements. SDLLME was successfully applied as an extracting method for the preconcentration of a hydrophobic chelate of Pb with 1-(2-pyridylazo)-2-naphthol (Pb-PAN) from a real water system. Then hydrophobic-enriched Pb-PAN-SPS was treated with a 1.5 mol L−1HNO3and CO2purge for different time intervals, to switch back to its miscible polar hydrophilic monophasic state. The recovery of SPS was carried out by heating at 55 °C and purging with N2gas. The SPS was easily recycled up to 12 times with >2% loss of efficiency of the developed method. Under the optimized experimental conditions, the limit of detection and the enhancement factor were determined to be 0.25 μg L−1and 50, respectively.

AbstractA new solid phase extraction method using hair as a adsorbent has been developed for beryllium(II) prior to its spectrophotometric determination using chrome Azurol S. The effects of various variables such as pH, sample and eluent flow rates, eluent volume and concentration, sample volume, and interfering ions on the quantitative recoveries of beryllium(II) were investigated. The multivariate strategy was applied to screen out the multifactor and estimate the optimum values of experimental factors for the recovery of beryllium(II) using solid phase extraction. Calibration graph was linear in the range of 0.046–20 μg L−1with correlation coefficient (r2 = 0.987). The sensitivity (limit of detection (LOD)) and selectivity (preconcentration factor) of the proposed methods were 0.028 and 50, respectively. Validity and accuracy of the developed solid phase extraction method were checked by analysis of a certified reference water for Trace Elements (TM-28.3) and a real water samples by standard addition method, the relative recoveries >96% were obtained. The method was successfully applied for the determination of beryllium(II) in natural water samples.

A new solid phase extraction method using hair as a adsorbent has been developed for beryllium(II) prior to its spectrophotometric determination using chrome Azurol S. The effects of various variables such as pH, sample and eluent flow rates, eluent volume and concentration, sample volume, and interfering ions on the quantitative recoveries of beryllium(II) were investigated. The multivariate strategy was applied to screen out the multifactor and estimate the optimum values of experimental factors for the recovery of beryllium(II) using solid phase extraction. Calibration graph was linear in the range of 0.046–20 μg L−1with correlation coefficient (r2 = 0.987). The sensitivity (limit of detection (LOD)) and selectivity (preconcentration factor) of the proposed methods were 0.028 and 50, respectively. Validity and accuracy of the developed solid phase extraction method were checked by analysis of a certified reference water for Trace Elements (TM-28.3) and a real water samples by standard addition method, the relative recoveries >96% were obtained. The method was successfully applied for the determination of beryllium(II) in natural water samples.

An environmentally friendly ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLμE) method was developed for the preconcentration of trace levels of iron (Fe) in serum samples of hepatitis B and C patients, prior to its determination by flame atomic absorption spectrometry. The procedure was based on complexation of iron with a chelating reagent, 8-hydroxyquinoline (oxine), whereas an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6], and ethanol were chosen as extracting and dispersive solvents, respectively. The factors affecting the efficiency of IL-DLLμE, such as the amount of IL, pH, centrifugation time and ligand concentration, were investigated in detail. The resulting data indicated that the coexisting cations and anions ions had no apparent influence on determination of Fe at trace levels. Under optimal experimental conditions, the enhancement factor and the limit of detection were 59.1 and 1.29 μg L−1, respectively. The relative standard deviation for five replicate determinations of Fe at 50 μg L−1was calculated to be <5.0%. The developed method was validated by determining Fe in a certified reference material of serum. The proposed method can be successfully used for the enrichment of Fe in acid digested serum samples of female hepatitis B and C patients.

We have developed a simple ultrasonic-assisted ionic liquid-based microextraction (US-ILME) method for trace levels of aluminum (Al3+), in water, blood, and urine samples, followed by atomic absorption spectrometry with a nitrous oxide–acetylene flame. An ionic liquid, 1-hexylpyridinium hexafluorophosphate [Hpy][PF6], was used as the extraction solvent, and 8-hydroxyquinoline (oxine), was used as the Al3+chelating agent. A multivariate strategy was employed to evaluate five factors/variables (concentration of the chelating agent, pH, amount of ionic liquid, sonication time and centrifugation time) at once, whereas a central composite design was used to find the optimum values of the significant variables. The multivariate strategy was used to estimate the optimum values of experimental factors that influence the efficiency of US-ILME. Under the optimum experimental conditions, the limit of detection (3 s) and enrichment factor were 0.66 μg L−1and 113, respectively. The relative standard deviation (RSD) for six replicate determinations of 10 μg L−1of Al3+was 1.7%. The method was validated by the analysis of certified reference materials and applied successfully to the determination of Al3+in different types of drinking water, and in blood and urine samples of kidney failure patients. The data indicated that the levels of Al3+were significantly higher in kidney failure patients compared with healthy referents (p< 0.01).

A green miniaturized dispersive ionic liquid nano-emulsion extraction (NDILE) method has been developed for the preconcentration of trace levels of cadmium (Cd) in canal, tap and waste water samples. In the proposed approach, 1-butyl-3-methylimidazolium hexafluorophosphate, [C4mim][PF6], was dispersed into nano-emulsions by a low-energy emulsification phase inversion method, stabilized by a nonionic surfactant (TX-114). The influence of variables such as ionic liquid volume, concentration of the surfactant, stirring rate and time was studied and optimized. The morphology of the nano-emulsion system and its stability were evaluated through visual assessment and optical light microscopy. Ionic liquid nano-emulsion (ILN) was used as a dispersive and extractive medium, due to its small size and high surface area, to enhance the extraction efficiency of Cd complexed with 8-hydroxyquinoline from aqueous media. Separation of stable ILN could be induced by the micellar cloud point extraction approach. Under optimum conditions, the limit of detection and enhancement factor were found to be 0.48 ng L−1and 180, respectively. Validation of the developed method was carried out by Cd determination using a certified reference material (SLRS-4 Riverine water) and the results were found to be in good agreement with the certified values. The proposed novel method was successfully applied for determination of Cd in real water samples.

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 μg/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.

A simple liquid–liquid microextraction termed as vortex-assisted liquid–liquid microextraction (VLLME) coupled to flame atomic absorption spectrometry for lead (Pb) determination is achieved through phase-partitioning phenomena of ionic surfactants in aqueous solution. In this procedure, the hydrophobic chelate of Pb with 1-(2-pyridylazo)-2-naphthol (PAN) was extracted into the fine droplets of 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], while using Triton X-100 (TX-100) as dispersing medium. Several variables including [C4mim][PF6] volume, pH of sample, TX-100 volume, concentration of PAN, centrifugation time and rate were considered to be studied. At optimum experimental values of significant variables, detection limit (LOD) and the enhancement factor (EF) were observed to be 0.307 μg L−1and 54.2, respectively. The relative standard deviation (RSD) of 10 μg L−1Pb was 4.09%. The coexisting ions showed no obvious negative outcome on Pb preconcentration. Validation of the developed method was carried out by Pb determination in “NIST-SRM 1515 Apple leaves” standard reference material and the results were found in good agreement with the certified values. The method was applied satisfactorily for the preconcentration of Pb in acid digested samples.