The present study was carried out to evaluate the possible exposure route of metals (Ag, Co, Cd, Pb Ni and Be) and their contaminated level in waste and natural water of different ecosystem by green miniaturized preconcentration methods. Green analytical chemistry mainly pursues the objectives of replacing toxic reagents, and miniaturizing and automating analytical methodologies, to minimize environmental and human hazards by replacing polluting methods with clean ones. The main theme of this research work to develop innovative green miniaturized preconcentration methodologies that could reduce efforts, uses and exposure of the toxic material to the environment, which could lead to number of health problems. F Cloud point extraction (CPE) has been used for the preconcentration and simultaneous determination of cadmium (Cd) and nickel (Ni), cobalt (Co) and lead (Pb) in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (8-HQ) as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (8-HQ and Triton X-114), temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS). The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, 0.22 and 0.52 for Cd and Ni, respectively. F Simultaneously evaluation of silver (Ag), cadmium (Cd), nickel (Ni), cobalt (Co) and lead (Pb) in water samples collected from fresh water canal receiving untreated effluents from an industrial area, of Sindh Pakistan. The analytes were preconcentrated by CPE using ammonium pyrrolidinedithiocarbamate (APDC) as a complexing agent and then entrapped in non-ionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). The surfactant rich phase was diluted with acidic ethanol prior to analysis by flame atomic absorption spectrometry. The variables affecting the complexation and extraction steps were investigated in detail. Under the optimum conditions, the preconcentration of 10 mL sample solutions, allowed preconcentration factor of 20-fold. The concentration of Ag, Cd, Ni, Co and Pb has shown a decreased trend from 46.5–6.96, 23.0–8.92, 30.2–12.8, 14.2–4.45 and 15.3–5.32 μg L−1, respectively from initial entrance of waste water along the downstream of canal. F Easy and innovative non-dispersive ionic liquid based microextraction (NDILME) has been developed for preconcentration of trace level of cadmium (Cd) in aqueous real surface water samples prior to couple with graphite furnace atomic absorption spectrometry (GFAAS). A 140 cm long narrow glass column containing aqueous solution of standard/sample was used to increase phase transfer ratio by providing more contact area between two medium (aqueous and extractive), which drastically improve the recoveries of labile hydrophobic chelate of Cd - ammonium pyrrolidine dithiocarbamate (APDC), into ionic liquid 1-butyl-3-methylimidazolium hexafluoro phosphate [C4mim][PF6]. Different aspect of the desire method have been investigated and optimized. Under the optimized key experimental variables, limit of detection (LOD) and enhancement factor (EF) were achieved to be 0.5 ng L−1 and 150, respectively. Application of the model method was productively performed by analysis of Cd in real surface water samples (tap and sea). F 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. Under optimum conditions, the limit of detection and enhancement factor were found to be 0.48 ng L-1 and 180, respectively. F Single drop microextraction (SDME) combined with electrothermal atomic absorption spectrometry was proposed for the determination of trace levels of silver(I)) in fresh and waste water samples. The analyte was extracted from aqueous samples into a drop of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM] [PF6]), after complexation with 8-hydroxyquinoline (8HQ). The multivariate statistical tool was applied to find out the optimum values of experimental factors for the recovery of silver(I) in SDME. Under optimized condition the limit of detection (3 s) and enhancement factor were achieved 1.12 ng L−1 and 80, respectively. A highly appreciable and successful application of the methods was done in different fresh and waste water samples. F Innovative and green reversible switchable polarity solvent extraction (RSPS-E) method has been first time introduced as a preconcentration tool for the removal of toxic metal lead (Pb) in fresh and waste water samples, prior to connect with flame atomic absorption spectrometry (FAAS). In present study a switchable polarity solvent (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and decanol were reversibly switch on and off from heterogeneous biphasic nonpolar hydrophobic to homogenous monophasic polar hydrophilic phase in aqueous medium by exposing to antisolvent trigger (CO2) for 1-10 minutes. Then SPS of polar microemulsions was switched-on by bubbling CO2, and switched-off by heating in the range of 40-70°C in presence of N2 gas. The changes obtained in the structures and physical properties of SPS due to switching from low polarity to high polarity were confirmed by, FTIR spectrophotometry and conductivity measurements. The RSPS-E was successfully applied as an extractive medium for hydrophobic chelate of lead with 1-(2-pyridylazo)-2-naphthol (Pb-PAN) and extracted in SPS. Then hydrophobic enrich Pb-PAN-SPS was treated with 1.5 mol L-1 HNO3 and purge CO2 for different time interval, to switches back to its miscible polar hydrophilic monophasic state. The recovery of SPS solvent was carried out by heating at 55°C and purging of N2 gas. The SPS solvent easily recycled up to 12 time with >2 % loss of efficiency of the developed method. The different variables such as, pH, concentration of complexing agent, pressure and purging time of CO2, heating rate were optimized. Under the optimized experimental variables, the enhancement factors (EF) with limits of detection (LOD) were obtained to be 0.25 μg L−1 and 50, respectively. F 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 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. The sensitivity (LOD) and capability (preconcentration factor) of the proposed methods were 0.028 and 50, respectively. The method was successfully applied for the determination of beryllium(II) in natural water samples. F An innovative and simple miniaturized solid phase microextraction (M-SPME) method, using the micropipette tip packed with activated carbon cloth (ACC) in a syringe system was developed for preconcentration and determination of silver(I) in the fresh and waste water samples. The size, morphology and elemental composition of activated carbon cloth have been characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The retention of the metal ions in the form of complexes on activated carbon cloth in a micropipette tip couple with syringe system was achieved by using ammonium pyrrolidine dithiocarbamate (APDC) as the complexing agent from 2 to 10 aspirating/dispensing cycles. The analyte retained on ACC micropipette tip syringe system were then eluted with 2.5 mol L-1 (HNO3) from 2 to 5 aspirating/dispensing cycles, and then injected directly into the electrothermal atomic absorption spectrometry (ETAAS) for analysis. The proposed method was successfully applied to real water samples. F Validity and accuracy the developed procedures was carried out by analysis of a different certified reference sample of water (CRM1634e), certified reference material (SLRS-4 Riverine water) and certified reference water for Trace Elements (TM-28.3) . Reliability of the proposed method was also checked by the standard addition method in a real sample, which gave satisfactory results." xml:lang="en_US