An efficient microchip electromembrane extraction online with high-performance liquid chromatography for the measurement of nicotine in high consumption vegetables.

INTRODUCTION: Nicotine, a highly addictive substance, is naturally produced in the Solanaceae family of plants, particularly tobacco. The presence of nicotine in plant foods has adverse effects on the lungs, kidneys, heart, and reproductive system. OBJECTIVE: A novel three-phase microchip flat electromembrane coupled with online high-performance liquid chromatography (HPLC) was developed to analyze nicotine in tomato, mushroom, eggplant, bell pepper, and red pepper. METHODS: The microchip was connected to the HPLC in online mode. All effective variables were optimized to achieve the best extraction response. The use of electric potential and 2-nitrophenyl octyl ether -5% di(2-ethylhexyl) phosphate as a modified supported liquid membrane (SLM) increased the sensitivity and selectivity. RESULTS: The optimal extraction voltage, extraction time, and ion balance were 40 V, 10 min and 0, respectively. The dynamic linear range was 0.5-1000 ng g-1. The obtained recovery, relative standard deviation, and enrichment factor were 98%, 7%, and 35, respectively. The limits of detection 0.4 ng g-1 and the limits of quantification were obtained 1.3 ng g-1. The highest (105.0 ng g-1) and lowest (3.4 ng g-1) concentrations of nicotine were obtained for eggplant and tomato, respectively. CONCLUSION: Selective electromembrane extraction of nicotine from the donor phase to the acceptor phase was performed by optimizing the main variables influencing the method mechanism. The new channel design in this analytical system and online injection increased efficiency, stability, and repeatability. The results revealed that this method is capable for the efficient determination of trace amount of nicotine in edible vegetables.

The selective extraction of dietary polyamines from chicken breast using the application of a lab-on-a-chip electromembrane and dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

Excessive dietary polyamines (PAs), including putrescine (PUT), spermine (SPM), and spermidine (SPD), have become a worldwide concern due to their carcinogenicity and reduced shelf life. A modern miniaturized on-chip electromembrane extraction (EME) has been applied to extract these compounds from chicken breast samples. This method is based fundamentally on ionic compounds' electrostatic attraction, diffusion, and solubility in the acceptor phase. The chemical structure of polyamines enables their efficient extraction using an electric driving force on a microchip device. HCl solution (0.1 mol L-1) was applied as an aqueous acceptor solvent. Dispersive liquid-liquid microextraction was performed after EME to facilitate joining three-phase EME to GC-MS and improve the merit figures. The total ranges of 3.77-7.89 µg g-1, 3.48-7.02 µg g-1, and 0.78-2.20 µg g-1 were acquired as PUT, SPM and SPD concentrations in chicken breast, respectively. The results demonstrate that the level of PAs in fresh chicken breast samples is not concerning, but it may reduce the quality of chicken meat over time. This novel analytical technique has several advantages: high recovery, substantial quickness, remarkable selectivity, and good enrichment factors. This emerging method could be generalized to other studies to analyze different foodstuffs.

Volatile N-nitrosamines in processed meat products: An approach for monitoring dietary exposure, assessing human risk, and evaluating variable correlations by principal component analysis and heat map.

Several epidemiological studies have reported a positive association between the consumption of processed meats containing N-nitrosamines (NAs) and the incidence of hepatocellular and colon cancer. The health risk assessment in this investigation was based on the concentration of six volatile N-nitrosamines (VNAs) (N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosomethylethylamine, N-nitrosopiperidine, N-nitrosodibutylamine, and N-nitrosodi-n-propylamine) found in processed meat products (sausage and kielbasa) in the Iranian market. Direct supported liquid membrane two-phase hollow fiber electromembrane extraction coupled to gas chromatography/mass spectrometry was used to analyse six VNAs. The mean concentration of the six VNAs in sausages and kielbasa was 38.677 ± 27.56 and 48.383 ± 35.76 µg/kg, respectively. The 95th percentile for the chronic daily intake of total VNAs for children (3-14 years) and adults (15-70 years) were calculated to be 5.06 × 10-4 and 1.09 × 10-4 mg/kg bw/day, respectively. The cancer risk assessment showed that the risk associated with NDEA was the highest among the other VNAs studied in Iranian processed meat, with a 95th percentile for the child and adult groups. Based on an incremental lifetime cancer risk (ILCR) value of ≤10-4 for the carcinogenic effects of exposure to a total of six VNAs, it indicates low concern for all age groups.

Release kinetic modeling of Satureja Khuzestanica Jamzad essential oil from fish gelatin/succinic anhydride starch nanocomposite films: The effects of temperature and nanocellulose concentration.

Fish gelatin (FG) and octenyl succinic anhydride starch (OSAS) composite films loaded with 1, 2, 3 and 4 wt% bacterial nanocellulose (BNC) and Satureja Khuzestanica Jamzad essential oil (SKEO) were achieved successfully and their physicochemical and release properties were investigated. The results revealed that incorporation of BNC improved the tensile strength which was associated with FE-SEM, FTIR and XRD. Moreover, this study focused on the release modeling of SKEO in 4, 25 and 37 °C from nanocomposite films using different release kinetic and Arrhenius models. Also, analysis of variance-simultaneous component analysis (ASCA) and exploratory data visualization by principal component analysis (PCA) were carried out to investigate the effects of two controlled factors. Consequently, the Peleg model showed the best fitting of experimental data. The activation energies decreased by increasing the BNC concentration. This research demonstrated the nanocomposite film containing SKEO would be a suitable candidate for active food packaging.

The Measurement of Hazardous Biogenic Amines in Non-Alcoholic Beers: Efficient and Applicable Miniaturized Electro-Membrane Extraction Joined to Gas Chromatography-Mass Spectrometry.

The determination of biogenic amines (BAs) as serious food contaminants and chemical indicators of unwanted microbial contamination or deficient processing conditions in non-alcoholic beers is of great interest for the beverage industries. In the present investigation, the combination of hollow fiber-electro-membrane extraction (HF-EME) and dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC/MS) was applied for the analysis of histamine, putrescine, tyramine, cadaverine in non-alcoholic beers. EME is fundamentally based on the electrostatic attraction, diffusion and solvability of analytes in a selected acceptor phase. This membrane-based extraction technique promoted selectivity and the enrichment factor. The DLLME process reduced the volumes of organic solvents and make the coupling of HF-EME to the CG/MS conceivable. The leading variables, which have a great effect on extraction recovery, were optimized. The relative standard deviation was achieved between 4.9 and 7.0%. The recoveries were between 94% and 98%. The limit of detection and limit of quantification were found to be 0.92-0.98 ng mL-1 and 3.03-3.23 ng mL-1, respectively. The enrichment factor was calculated in the range 36-41. The achievements revealed that putrescine and tyramine, with concentrations of 3.87 and 2.33 µg g-1, were at the highest concentration in non-alcoholic beers. This offered method with great benefits could help beverage industries to monitor the concentration of BAs in beers and control them.

New and efficient direct-SLM two-phase hollow fiber electromembrane extraction coupled to GC/MS for the analysis of nitrosamines in different types of sausage: Investigation of meat type, meat percent and cooking methods.

The potent two-phase hollow fiber electromembrane extraction technique coupled to gas chromatography mass spectrometry (HF-EME/GC-MS) was proposed for the determination of six types of carcinogen nitrosamines in sausages samples. Two steps of sample digestion were accomplished for the complete removal of fat globules and efficient release of target analytes. The extraction principle was based on electro-migration of target analytes via specific fiber to extraction solvent. 2-Nitrophenyl octyl ether (NPOE) was dexterously employed as both supported liquid membrane and extraction solvent, which is compatible with GC-MS. After the extraction process, the NPOE containing nitrosamines was directly injected to GC-MS without extra steps requirement to reduce analysis time. The consequences revealed that N-nitrosodiethylamine (NDEA) as the most potent carcinogen has the highest concentration in fried and oven-cooked sausages with 70% of red meat. The meat type and amount and also cooking process could significantly effect on nitrosamines formation.

Investigation of cocoa and cinnamon effect on acrylamide formation in cakes production using GC/MS method: A risk assessment study.

This study was conducted with the aim of investigating the effect of cinnamon and cocoa on the formation of acrylamide in cake samples and their carcinogenic and non-carcinogenic risks. The cake samples were prepared using alkaline extraction, xanthidrol derivative and micro-extraction, then injected into a gas chromatography-mass spectrometry (GC-MS) to identify acrylamide. The maximum and minimum mean concentration of acrylamide among samples was related to the cinnamon cakes (212.28 ng/g) and the cocoa cake samples (10.14 ng/g), respectively. Acrylamide concentration for unflavored samples, cinnamon cake samples and cocoa cake samples were 61.86 ng/g, 169.38-212.28 ng/g and 10.14-44.64 ng/g, respectively. Human health risk assessment based on Monte Carlo simulation (MCS) indicated that the target hazard quotient and incremental lifetime cancer due to ingestion of acrylamide formation in cake samples for adults and children were in the acceptable limits (THQ > 1 and CR > 1E-4). In conclusion, cocoa flavor was able to decrease the concentration of acrylamide in cakes. According to the results, it is necessary to measure the amount of acrylamide in consumer cakes by regulatory organizations.

Effect of sage seed gum film incorporating Zataria multiflora Boiss essential oil on the storage quality and biogenic amine content of refrigerated Otolithes ruber fillets.

The effect of an edible film based on sage seed gum (SSG) incorporating 3 % Zataria multiflora Boiss essential oil (ZEO) was investigated on the storage quality and shelf life of tiger-tooth croaker (Otolithes ruber) fillets during storage at 4 ± 1 °C compared to the control film (SSG film without ZEO) and the Cellophane. The SSG-ZEO film significantly decelerated microbial growth (evaluated by total viable count, total psychrotrophic count, pH, TVBN) and lipid oxidation (evaluated by TBARS) compared to the others (P ˂ 0.05). The antimicrobial activity of ZEO was the highest and the lowest on E. aerogenes (MIC: 0.196 µL/mL) and P. mirabilis (MIC: 0.977 µL/mL), respectively. E. aerogenes was identified as an indicator biogenic amine-producer in O. ruber fish at refrigerated temperature. The active film significantly lowered biogenic amine accumulation in the samples inoculated with E. aerogenes. A clear relationship was observed between the release of ZEO's phenolic compounds from the active film to the headspace and the reduction of microbial growth, lipid oxidation, and biogenic amine production in the samples. Consequently, SSG film containing 3 % ZEO is proposed as a biodegradable antimicrobial-antioxidant packaging to extend the shelf life and decrease the biogenic amine production in refrigerated seafood.

New and efficient magnetic nanocomposite extraction using multifunctional deep eutectic solvent based on ferrofluid and vortex assisted-liquid-liquid microextraction: Determining primary aromatic amines (PAAs) in tetra-packed fruit juices.

In this work, a novel magnetic nanocomposite solvent (MNCS) based on ferrofluid and multifunctional deep eutectic solvent (MDES) was synthesized and applied in vortex assisted-liquid-liquid microextraction (VA-LLME). The ferrofluid has been composed from zirconium phosphate (modified magnetic graphene oxide) and tetrabutylammonium bromide-octanoic acid deep eutectic solvent (MGO/α-ZrP@TBAB-OA). This efficient method was employed to determine primary aromatic amines including aniline, 4-methoxyanniline, 4,4'-diaminodiphenylmethane, orthotoluidine, 2,6-dimethylaniline, 2-naphtylamine in tetra-packed juice samples. The proposed method showed the excellent extraction efficiency of PAAs according to strong interactions of new extraction solvent including electrostatic, π-π, and hydrogen bonding attractions. The found levels of PAAs are lower than the limit of quantifications (2.0 µg L-1). Therefore, the migration of PAAs from packaging to the juice samples is lower than permitted level (<10 µg kg-1). The results indicated high potential use of the offered method to analyze aromatic amine compounds in foodstuff and biologic samples in the future.

Food safety and quality assessment: comprehensive review and recent trends in the applications of ion mobility spectrometry (IMS).

Ion mobility spectrometry (IMS) is an analytical separation and diagnostic technique that is simple and sensitive and a rapid response and low-priced technique for detecting trace levels of chemical compounds in different matrices. Chemical agents and environmental contaminants are successfully detected by IMS and have been recently considered to employ in food safety. In addition, IMS uses stand-alone or coupled analytical diagnostic tools with chromatographic and spectroscopic methods. Scientific publications show that IMS has been applied 21% in the pharmaceutical industry, 9% in environmental studies and 13% in quality control and food safety. Nevertheless, applications of IMS in food safety and quality analysis have not been adequately explored. This review presents the IMS-related analysis and focuses on the application of IMS in food safety and quality. This review presents the important topics including detection of traces of chemicals, rate of food spoilage and freshness, food adulteration and authenticity as well as natural toxins, pesticides, herbicides, fungicides, veterinary, and growth promoter drug residues. Further, persistent organic pollutants (POPs), acrylamide, polycyclic aromatic hydrocarbon (PAH), biogenic amines, nitrosamine, furfural, phenolic compounds, heavy metals, food packaging materials, melamine, and food additives were also examined for the first time. Therefore, it is logical to predict that the application of the IMS technique in food safety, food quality, and contaminant analysis will be impressively increased in the future. HighlightsCurrent status of IMS for residues and contaminant detection in food safety.To assess all the detected contaminants in food safety, for the first time.Identified IMS-related parameters and chemical compounds in food safety control.

Occurrence of Aflatoxins in Commercial Cereal-based Baby Foods in Iran: A Probabilistic Risk Assessment to Health.

The aim of this study was to assess the occurrence of Aflatoxins (AFs) including B1, B2, G1 and G2 in commercial cereal-based baby foods by HPLC-FLD method in Iran and related risk assessment in three baby age groups (6-12, 12-18, and 18-24 months) using Monte Carlo simulation approach. Results showed an occurrence ranging from 20% to 60% for B1, B2, and G2 aflatoxins, while AFG1 was not detected in any assessed samples. Exposure and risk assessment was estimated to be two groups (aflatoxin B1 and total aflatoxins). The highest estimated dietary exposure to both AFB1 and total AFs was estimated for 6-12 months aged babies, representing 5.81 ng/kg BW/day and 8.55 ng/kg BW/day, respectively. Overall, the margin of exposures to AFB1 and total AFs were lower than 10,000 in all age groups, indicating a health concern about AFB1 and total AFs exposure through cereal-based baby food consumption. High cancer risk for high consumers (P95) of baby food was also estimated in all age groups, calling for immediate intervention due to serious claims that AFB1, is a highly carcinogenic component, causes hepatocellular carcinoma. Risk ranking results indicated the presence of AFB1 is classified as high risk for babies who consume cereal-based foods, which demands the attention of risk managers to reduce or eliminate this risk for the most vulnerable sector of society, whose aged <24 months.

Response Surface Methodology of Quantitative of Heterocyclic Aromatic Amines in Fried Fish Using Efficient Microextraction Method Coupled with High-Performance Liquid Chromatography: Central Composite Design.

Meat and meat products are indispensable part of our diet. Heat processing of these tasty foods such as fried fish causes to form heterocyclic aromatic amines (HAAs). The sources of heating have directly affected on the level and type of HAAs. In this research, 2-amino-1-methyl-6-phenylimidazo [4'5-b] pyridine (PhIP), 2-amino-3-methylimidazo [4,5-f]quinolone (IQ), 2-amino-3,4-dimethylimidazo [4,5-f] quinoline (MeIQ) and 2-amino-3,4-dimethylimidazo [4,5-f] quinoxaline (MeIQx) were determined using an efficient analytical methodology coupled with high-performance liquid chromatography. The effective parameters were optimized by central composite design. The results of this survey demonstrated that rang of relative standard deviation were between 4.5 and 8.2, extraction recoveries were obtained 86-97% and limits of detection were between 0.40 and 0.63 for 4 HAAs. The amounts of HAAs found in 20 different fried fish samples were between 0 and 4.8 ng g-1. PhIP with 1.57 ng g-1 and MeIQ with 2.08 ng g-1 have the lowest and highest average level of HAAs, respectively.

Effect of chicken raw materials on physicochemical and microbiological properties of mechanically deboned chicken meat.

Excessive consumption of red meat is associated with various diseases including coronary heart diseases and cancer. Lower health-related problems of chicken meat, consumption of chicken meat, and mechanically deboned chicken meat (MDCM) have been increased due to their cheaper prices. Thereby, chemical, microbial, and physical causes of chicken meat losses and the safety aspects are needed to be fully considered to save food by improved application of chicken meat and its by-product. This study investigated the effects of chicken classes, layer, and broiler, and different carcass cuts, fillet, skeleton, and the whole carcass, on physicochemical, protein, fat, ash, moisture, pH, and peroxide, and microbiological, total plate counts, Escherichia coli, Staphylococcus aureus, Campylobacter, and Salmonella, characteristics as well as introducing content changes of metal elements iron, calcium (Ca), lead, cadmium, and arsenic in MDCM. The highest values of physicochemical characteristics, calcium, iron, and heavy metals were observed in deboned layer chicken carcass and deboned broiler skeleton (p<0.05). Although Escherichia coli was detected in all of the treatments, Salmonella, Staphylococcus aureus, and Campylobacter contamination were found only in the deboned layer and broiler skeleton. In conclusion, the application of MDCM by-products in meat products without thermal processing is not recommended. The broiler and layer skeleton MDCMs are not suitable for human consumption due to the high contents of heavy metals. However, the whole carcasses of layer chickens are suitable to be mutually used in MDCM at the end of the egg laying period.

Acrylamide content of collected food products from Tehran's market: a risk assessment study.

Acrylamide concentration in food products collected from the Tehran market was investigated by the aid of a dispersive liquid-liquid microextraction (DLLME) system coupled with gas chromatography-mass spectrometry (GC-MS). Also, the dietary exposure distribution and related potential risk for acrylamide ingestion were estimated by the Monte Carlo simulation (MCS). The highest and lowest mean concentration of acrylamide was detected in coffee and roasted nuts samples as 549 and 133 µg/kg, respectively. The mean acrylamide dietary exposure values for children (3-10 years), adolescents (11-17 years), adults (18-60 years), and seniors (61-96 years) were estimated to be 1.81, 1.02, 0.61, and 0.53 µg/kg body weight (BW)/day, respectively. In all age groups, except children, the estimated exposure in men and boys was higher than that in women and girls. Bread, despite containing low acrylamide content groups (157 µg/kg while compared with other, except roasted nuts), showed with the highest contribution rate in all age groups due to its high consumption rate. The estimated incremental lifetime cancer risk (ILCR) for all age groups was noted as greater than 10-4 indicating serious risk to the population. Moreover, the margin of exposure (MOE) values based on carcinogenicity showed health concern to all age groups (< 10,000). Regarding the non-carcinogenic risk, the target hazard quotient (THQ) was lower than 1, and MOE based on neurotoxicity was higher than 125 (safety thresholds), which represented negligible and ignorable risk in all age groups except in a small group of children and adolescents. Graphical abstract.

Quantitative determination of trace phenazopyridine in human urine samples by hyphenation of dispersive solid-phase extraction and liquid-phase microextraction followed by gas chromatography/mass spectrometry analysis.

Magnetic dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid-phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene-pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid-liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. Calibration curve was linear in the range of 0.5-250 ng/mL (R2  = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra- and interday precisions (RSD%, n = 3) of the method were in the range of 4.6-5.4% and 4.0-5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0-89.0%.

Reduction in Acrylamide Formation in Potato Crisps: Application of Extract and Hydrocolloid-Based Coatings.

ABSTRACT: Two different potato chip coatings-aqueous extracts including Zataria multiflora and Allium hirtifolium at concentrations of 1, 3, 5, and 7% and hydrocolloids individually or in combination-were used to decrease acrylamide content, and their effects on the characteristics of the product were then investigated. According to the results, the incorporation of hydrocolloids as the coating was more efficient in the reduction of acrylamide production than with the extracts. Also, the application of each extract and hydrocolloids individually can be considered a more efficient technique for acrylamide reduction than their mixture. In this regard, the economic aspects of the application of hydrocolloids in the coating of fried potato crisps can be evaluated.

Heterocyclic aromatic amines in doner kebab: Quantitation using an efficient microextraction technique coupled with reversed-phase high-performance liquid chromatography.

The safety of doner kebab as a traditional Middle East tasty food can threaten via the formation of dangerous compounds such as heterocyclic aromatic amines during heat process. In this regard, the current investigation was devoted to measuring of 4 HAAs (2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)) in doner kebab samples with an innovative microextraction technique combined with high-performance liquid chromatography. The limit of detection was in the range of 4.8 and 5.3 ng/g, while relative standard deviations were between 6.5% and 8.3%, and recoveries were calculated in the range of 89%-97%. The most and the least total mean values of HAA levels were 13.30 ng/g for MeIQx and 5.0 ng/g for IQ. The proposed method showed a high capability to extract trace amount of HAAs from a complex matrix such as doner kebab. Also, this technique is easy, high sensitive, selective, accurate and efficient.

Haas in grilled meat: Determination using an advanced lab-on-a-chip flat electromembrane extraction coupled with on-line HPLC.

In this research, a new design of channels in a lab-on-a-chip device with flat electromembrane extraction (LOC-FLEME) was fabricated. The latter microfluidic device was successfully used for the determination of 2-amino-3-methyl imidazo[4-5-f]quinolone (IQ), 2-amino-3, 8-dimethlylimidazo[4, 5-f]quinolone (MeIQ), 2-amino-3,4- dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4, 5-b] pyridine (PhIP) in grilled meat, by on-line coupling of LOC-FLEME to an HPLC system. Important parameters in extraction process were optimized. The calibration curve was linear over the range of 5-1000 ng g-1 with a correlation coefficient higher than 0.9991. The relative recoveries were between 95 and 98% at three concentration levels. The relative standard deviations were 4.1 to 6.0%. The limits of detection were 1.4, 0.9, 1.7 and 1.3 ng g-1 for PhIP, IQ, MeIQ and MeIQx, respectively. Sums of 4HAAs concentrations for different grilled meat samples were 2.75-6.17 ng g-1.

Water resistance and mechanical properties of low methoxy-pectin nanocomposite film responses to interactions of Ca2+ ions and glycerol concentrations as crosslinking agents.

To achieve a low methoxy-pectin nanocomposite film with maximum resistance to water and acceptable mechanical properties, the interactions of different glycerol concentrations and Ca2+ ions in both steps of crosslinking on the swelling degree (SD) and mechanical properties of prepared films were investigated using response surface methodology (RSM). Accordingly, quadratic second-order models were fitted to the SD and tensile strength responses; while the cubic model demonstrated a good relation between independent variables and elongation at break respectively. As a compromise between water resistance and mechanical properties of the prepared films, the use of 0.5% Ca2+, 0.75% Gly1 and 7.5% Gly2 is suggested as the optimum condition. Generally, crosslinking of pectin polymer with Ca2+ cations in the second step along with incorporation of nanocellulose into pectin film led to the formation of more flexible and completely water insoluble pectin nanocomposite film in comparison to the other polymers crosslinked with Ca2+ cations.

Central Composite Design for Dispersive Liquid-liquid Microextraction of 25-hydroxy-cholecalciferol in Human Serum.

The human body's vitamin D levels are determined by measuring the level of 25-hydroxy-vitamin D3 (25-OH-vitamin D3) in human serum. In this research, a fast, simple, efficient and highly sensitive low-density solvent based on dispersive liquid-liquid microextraction (DLLME) was employed for the successful determination of 25-OH-vitamin D3 from complex human serum matrices. Reversed phase high-performance liquid chromatography was used as a powerful technique. The important parameters in the low-density solvent-DLLME method were optimized using response surface methodology based on central composite design. The calibration curves displayed a high level of linearity (R2 > 0.997) for 25-OH-vitamin D3 in the range of 2-500 ng mL-1. The limit of detection and limit of quantitation were 0.6 ng mL-1 and 1.9 ng mL-1, respectively. The relative standard deviation for the seven analyses was 7.1%. The relative recoveries of vitamin D3 in spiked human serum samples were between 85% and 97%. The amount of 25-OH-vitamin D3 in samples was determined using the proposed method and acceptable results were reported.