Self-made Device Research Articles

Design and validation of a simple device for insufflation of dry powders in a mice model

Delivery of inhalational dry powders (DPs) to the lung of mice is pivotal for pre-clinical pharmacokinetic and pharmacodynamic investigations. Although several devices have been reported, their application is always limited by many factors, including complicated design, high price, commercially discontinued status, as well as requirement of special skills. Here, we have introduced a simple device for non-invasive and precise delivery of DPs in mice. We set up the self-made device using a 20 G cannula tube and a 1 mL syringe. Subsequently, it was validated in terms for proper installation, delivery of dry powder and safety. Taken together, we believe that this device will be helpful in pre-clinical studies, especially in laboratory experiments, for respiratory drug delivery in small animal models.

Effect of Al on Expansion Behavior of Mg–Al Alloys During Solidification

The cooling curves and the change of contraction/expansion during solidification and cooling were tested by using a self-made device which could achieve the one-dimensional contraction instead of three-dimensional contraction of the casting. Then, the effects of Al content (0, 1.1, 3, 5, 10, 12.9, 15, 17, 19, 22, 24 and 30 wt%) on the thermal contraction/expansion of the binary Mg–Al as-cast alloys during solidification were obtained. The results showed that expanding instead of contraction was present in Mg–Al alloys with the addition of 0–30 wt% Al during solidification. The values of expansion significantly increased at first and then decreased with the increase in Al content. And the maximum expansion ratio of 0.44% (maximum expansion value: 0.841 mm) was present in the Mg–15 wt% Al alloy. Contraction instead of expansion occurred once the temperature drops to the temperature corresponding to the expansion value in total, indicating the occurrence of a continuous expansion during the solidification process in mushy zone for the Mg alloys with Al addition of 5–30 wt%. The expansion value in total consisted of two parts: the expansions occurring in the liquid-phase zone and mushy zone. The expansion in liquid zone was present in every Mg–Al alloy, and it contributed to the most proportion of the total expansion value when the Al content in Mg–Al alloy was lower than 10 wt% or higher than 22 wt%. However, the total expansion value was mainly determined by the solidification behavior in mushy zone when the Al content was among 10–22 wt% in Mg–Al alloys.

Selective Water Shutoff Mechanism of Double-Crosslinked Gel-Type Selective Plugging Agent (Org)

In this paper, the selective plugging capacity of ORG plugging agent under different temperatures, different permeabilities and the same injection pressure was studied by using a self-made selective plugging simulation device. With the increase of core permeability, the water plugging rate and oil plugging rate increased, while the water plugging rate and oil plugging rate were low due to the low permeability core, but all showed good selective water plugging capacity. And the theory of molecular action of cationic polymer adsorption on rock surface was studied in the ORG plugging agent. The plugging mechanism of ORG plugging agent in the rock pore was studied.

Influence of electromagnetic compound treatment on microstructure and properties of cemented carbide

In order to study the effect of external field treatment on mechanical properties, cutting performance, microstructure of cemented carbide, the cemented carbide samples were treated by different magnetic field frequency (f=0.3 Hz, 0.4 Hz, 0.5 Hz) processing methods using self-made electromagnetic compound treatment device. On the basis of the study of this method, the electromagnetic compound treatment method was proposed to couple pulsed magnetic field and pulsed current. The results show that after the treatment of magnetic field frequency, the hardness of the sample slightly higher than that untreated sample, the increase value of percent between 0.5% and 1.3%, the value of hardness was 1594.72 HV, 1587.76 HV, 1582.45 HV, the longer the magnetization time, the higher the hardness; the cutting performance was increased, which means the tool life was increased, the increase value of percent from 4.5% to 7.0%. After electromagnetic compound treatment, the increase value of percent was 1.7% and 2.3%, the value of hardness was 1601.6 HV, 1609.82 HV; the tool life was increased 7.5% and 8.4%. After external field treatment, the angular state of wolfram carbide (WC) particle was transformed into smooth state and was more evenly distributed.

Feasibility of screw placement on posterior occipital condyle assisted by occipital tangent angulation

Objective: To investigate the practicability of occipital tangent angle in assisting posterior occipital condylar screw placement and to verify the safety and accuracy of self-made screw placement device for auxiliary screw. Methods: Occipito-cervical region specimens of 12 adult corpses were selected and scanned by thin-cut CT examination.The three-dimensional reconstruction of occipital and atlas was simulated for each specimen, and 3-matic software was used to measure the setting parameters, including occipital tangent angle, head obliquity, internal inclination angle, length of the screw and the distance from the inferior margin of hypoglossal canal to the screw axis.Using the self-designed occipital condylar screw placement device, combined with occipital tangent angle, internal inclination angle and insertion point, the posterior occipital condylar screw specimen was inserted with nails with assisting tool.The occipito-cervical region was reconstructed and scanned by thin-cut CT examination again after the operation to measuring the parameters of screw placement after actual screwing.The paired t test was used to compare the parameters of screw placement before and after operation. Results: Pre-operative three dimensional reconstruction of occipital condyle screw showed that the head obliquity was 5.3°±0.9°, the tangent angle was 14.9°±3.7°, the internal inclination angle was 28.1°±5.9°, and the length of screw insertion was (21.4±1.7) mm respectively; the distance from the inferior margin of hypoglossal canal to the screw axis was (4.74±0.36) mm.There was no significant difference in the parameters of analogue nailing between the left and right occipital condyles before the operation (t=-1.32, -0.48, 0.10, 0.23, 0.09, all P>0.05). The occipital condylar screw was safely implanted with screw placement device.The screw was located in the ideal nail insertion channel after operation by CT scan evaluation, without any injury to the hypoglossal canal, the atlanto-occipital articular surface and other structure.After the operation, the actual nailing parameters were measured: the head inclination angle was 5.2°±0.7°, the tangent angle was 15.1°±3.2°, the internal inclination angle was 28.2°±4.2°, the length of screw insertion was (21.5±1.7) mm, the distance from the inferior margin of hypoglossal canal to the screw axis was (4.54±0.29) mm.There was no significant difference between the left and right side in the actual screw placement parameters (t=-0.77, 0.82, 0.56, 0.22, 0.21, all P>0.05). It was found that there was no significant differences in the head obliquity, the occipital tangent angle, the internal inclination angle, length of screw entry, and the distance from the inferior margin of hypoglossal canal to the screw axis before and after the operation (t=0.56, -0.47, -0.18, -0.70, 1.89, all P>0.05). Conclusion: The occipital tangent angle can be measured directly in the process of posterior occipital condyle screw insertion to guide occipital condylar screw insertion, and the self-made occipital condylar screw placement device can effectively combine the three parameters: occipital tangent angle, head inclination angle and insertion point, which can improve the safety of posterior occipital condylar screw insertion.

Synergistic effect of sulphate-reducing bacteria and external tensile stress on the corrosion behaviour of X80 pipeline steel in neutral soil environment

X80 pipeline steel, which has a wide application prospect, is easily affected by sulphate-reducing bacteria (SRB) in typical neutral soil and causes stress corrosion cracking. Using a self-made experimental device, the stress corrosion cracking behaviour and mechanism of X80 pipeline steel under the synergistic effects of SRB and tensile stress in Shenyang soil were investigated through the slow strain rate test, electrochemical impedance spectroscopy, potentiodynamic polarisation technology and scanning electron microscopy. In a growth cycle, results showed that SRB quantity initially increased, decreased and peaked on the eight day. SRB improved the stress corrosion cracking sensitivity of X80 steel. When the amount of SRB was 8.7 × 103 cell/mL to 1.6 × 104 cell/mL, ductile fracture occurred in X80 steel, and mechanical factors could accelerate different forms of anodic dissolution induced by different amounts of SRB. When the SRB quantity increased by 1.7 × 104 cell/mL, brittle fracture occurred in X80 steel. The fracture mechanisms were anodic dissolution and hydrogen-induced cracking.

The effect of dynamic friction with wet fabrics on skin wetness perception

Purpose. To investigate the effect of cold stimulation (contacting wet fabric) and tactile stimulation (dynamic friction) on skin wetness perception: (a) wetness perception of fabric with different water transfer performance; (b) wetness perception of fabric with different water content; (c) wetness perception of fabric at different friction velocity with skin. Methods. Twenty participants were screened as reliable assessors using a 7-point wetness rating scale. The dynamic friction between skin and fabric was simulated by a self-made device with an adjustable speed controller. Each participant was asked to finish 18 assessments: 3 types of knitted fabric (cotton, polyester/spandex and Coolmax®) × 3 water contents (low, medium and high) × 2 friction velocities (30 and 90 mm/s). The subjective wetness perception and skin cooling rate were recorded during the experiments. Conclusions. The fabric type, water content and friction velocity significantly influence skin perceptual wetness. Fabric with good liquid moisture management property is perceived as significantly less wet, especially under a heavy sweaty state of the human body. The stronger wetness perception is perceived when fabric with a small frictional coefficient rubs skin at a lower friction velocity. The maximum transient thermal flow of fabric has a significantly positive correlation with wetness perception (r = 0.972).

Study on essential oil separation from Forsythia suspensa oil-bearing water body based on vapor permeation membrane separation technology

To investigate the feasibility of vapor permeation membrane technology in separating essential oil from oil-water extract by taking the Forsythia suspensa as an example. The polydimethylsiloxane/polyvinylidene fluoride (PDMS/PVDF) composite flat membrane and a polyvinylidene fluoride (PVDF) flat membrane was collected as the membrane material respectively. Two kinds of membrane osmotic liquids were collected by self-made vapor permeation device. The yield of essential oil separated and enriched from two kinds of membrane materials was calculated, and the microscopic changes of membrane materials were analyzed and compared. Meanwhile, gas chromatography-mass spectrometry (GC-MS) was used to compare and analyze the differences in chemical compositions of essential oil between traditional steam distillation, PVDF membrane enriched method and PDMS/PVDF membrane enriched method. The results showed that the yield of essential oil enriched by PVDF membrane was significantly higher than that of PDMS/PVDF membrane, and the GC-MS spectrum showed that the content of main compositions was higher than that of PDMS/PVDF membrane; The GC-MS spectra showed that the components of essential oil enriched by PVDF membrane were basically the same as those obtained by traditional steam distillation. The above results showed that vapor permeation membrane separation technology shall be feasible for the separation of Forsythia essential oil-bearing water body, and PVDF membrane was more suitable for separation and enrichment of Forsythia essential oil than PDMS/PVDF membrane.

Test of Corrosion Resistance of Heat Insulating Materials to Cryolite Vapor

Heating insulating materials were often eroded by cryolite vapor when they were used outside the wall of energy saving aluminum electrolysis cell. Insulating effect of aluminum electrolytic cell became worse with the time of extension. According to service environment of the aluminum electrolytic cell, a set of test methods was put forward. The physical properties, phase compositions and microstructures of the heating insulating materials under the different test conditions were studied by self-made test device. The results showed that test and characterization the corrosion resistance to cryolite vapor was of great significance for evaluating the performance decline and exploring the mechanism of corrosion resistance in the service process of materials. It provided a guidance to develop and choose the appropriate insulating materials.

A 3-DOF hemi-constrained wrist motion/force detection device for deploying simultaneous myoelectric control.

For describing the state of the wrist, either the force or movement of wrist can be measured as the training target in the simultaneous electromyography control. However, the relationship between the force and movement is so complex that only the force or movement is not precise enough to describe its actual situations. In this paper, we propose a novel platform that can acquire three degrees of freedom (DOF) wrist motion/force synchronously with multi-channel electromyography signals in a hemi-constraint way. The self-made wrist force-movement mapping device establishes a stable relationship between the wrist movement and force. Meanwhile, the elicited wrist movement can be directly fed back to the subjects via laser cursor. The information of the cursor can directly reflect the 3-DOF movement of the wrist without any decoupling algorithms. Through this platform, the support vector regression model learned from the training data can well predict the arbitrary combinations of 3-DOF wrist movements. The cross-validation result indicates that the regression accuracy of free 3-DOF movements can reach a similar performance to that of 2-DOF regular movements (in terms of R2, regular movement vs. free movement, p > 0.1). Graphical abstract The hemi-constrained platform used for detecting 3-DOF wrist movements.

Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters.

Chitosan oligosaccharide ameliorates acute lung injury induced by blast injury through the DDAH1/ADMA pathway.

ObjectiveTo investigate the protective effect of chitosan oligosaccharide (COS) on acute lung injury (ALI) caused by blast injury, and explore possible molecular mechanisms.MethodsA mouse model of blast injury-induced ALI was established using a self-made explosive device. Thirty mice were randomly assigned to control, ALI and ALI + COS groups. An eight-channel physiological monitor was used to determine the mouse physiological index. Enzyme linked immunosorbent assay was used to measure serum inflammatory factors. Hematoxylin-eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, immunofluorescence staining, real time-polymerase chain reaction and western blot assay were used to detect inflammatory reactions, oxidative stress and apoptosis.ResultsMice were sacrificed 24 hours after successful model induction. Compared with the ALI group, the heart rate, respiration and PCO2 were significantly lower, but the PO2, TCO2 and HCO3- were significantly higher in the ALI + COS group. Compared to ALI alone, COS treatment of ALI caused a significant decrease in the wet/dry lung weight ratio, indicating a reduction in lung edema, inflammatory cell infiltration, levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6 and nuclear factor kappa B mRNA and protein expression were reduced and IL-10 mRNA and protein expression was increased (P < 0.05). COS significantly inhibited reactive oxygen species, MDA5 and IREα mRNA and protein expressions, cell apoptosis and Bax and Caspase-3 mRNA and protein expressions, and significantly increased superoxide dismutase-1 mRNA expression, and Bcl-2 and Caspase-8 mRNA and protein expression (all P<0.05). COS significantly increased dimethylarginine dimethylaminohydrolase 1 (DDAH1) protein expression, and reduced ADMA and p38 protein expression (P< 0.05).ConclusionBlast injury causes inflammation, oxidative stress and apoptosis in the lung tissues of mice. COS has protective effects on blast injury-induced ALI, possibly by promoting DDAH1 expression and inhibiting ADMA and mitogen-activated protein kinase pathways.

Study on Cesium Adsorption/Desorption Behavior of Porous Nickel

A simplified two-dimensional mode of is established for the performance, characteristics and transportation behavior in cesium adsorption/desorption process. Subsequently the cesium absorption/ desorption ability of porous nickel were investigated by batch experiment on the condition that the pressure is lower than 10 Pa in self-made quarz vacuum device containing porous nickel with the appropriate structural features and parameters simulated above. The experiment results indicate that about 95% of cesium can be desorbed quickly and effectively with a stable process from the porous nickel show that the simulation model and the analysis method are correct and feasible which can be used as a basis for further study. According to the detailed simulation result, model reveal the considered porous nickel could be used for feasibility of cesium adsorption/desorption, which is fully meeting the application need of both higher storage capacity and stable desorption efficiency in lower pressure ambient condition.

Influences of ulinastatin on acute lung injury and time phase changes of coagulation parameters in rats with burn-blast combined injuries

Influences of ulinastatin on acute lung injury and time phase changes of coagulation parameters in rats with burn-blast combined injuries

Effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor in rats with skeletal muscle contusion

To observe the effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor (HGF) in rats with skeletal muscle contusion, and to explore the mechanism of acupuncture at opposite acupoints on skeletal muscle contusion. Fifty-four Sprague Dawley (SD) rats were randomly divided into a blank group (6 rats), a model group (24 rats) and an opposing needling group (24 rats). The model group and opposing needling group were further divided into 1-day subgroup, 3-day subgroup, 5-day subgroup and 7-day subgroup, 6 rats in each one. No intervention was given in the blank group, while the model of skeletal muscle contusion was established in the model group and opposing needling group by self-made contusion device. 24 hours after contusion, electroacupuncture (EA) was applied at "Zusanli" (ST 36) and the corresponding points of ashi points at health side for 15 min, once a day. The subgroups of opposing needling group were treated for 1 day, 3 days, 5 days and 7 days, respectively. No treatment was given in the model group. Samples were collected in the subgroups 1 day, 3 days, 5 days and 7 days after treatment. The morphological change of injured gastrocnemius muscle was observed by using microscope after HE staining. The positive cell rate of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. The expression levels of HGF protein and PCNA protein were observed by Western blot. ① The results of HE staining showed that, 1 day after contusion, the inflammatory cells of gastrocnemius muscle in the opposing needling group were less than those in the model group; 3 days and 5 days after contusion, myoblasts and myotubes in the opposing needling group were more than those in the model group; 7 days after contusion, the neonatal muscle cells in the opposing needling group were more than those in the model group. ② The results of immunohistochemistry showed that, 1 day, 3 days and 5 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly higher than that in the model group (all P<0.001); 7 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly less than that in the model group (P<0.001). ③ The results of Western blot showed that, 1 day, 3 days and 5 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly higher than that in the model group (all P<0.05); 7 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly lower than that in the model group (all P<0.05). Acupuncture at opposite acupoints could regulate the expression of HGF and promote the activation, proliferation, migration and differentiation of muscle satellite cells in rats with skeletal muscle contusion, which could speed up the process of skeletal muscle injury repair.

电化学处理酸洗废液制备氧化铁的研究

酸洗废液是制约金属建材行业发展的一大阻碍，酸洗废液的处理问题因此成为我国近几年来的热点研究问题之一。本文采用自制电化学装置对Fe2+浓度为1 g/L模拟酸洗废液的处理过程及实验产物进行分析，外加电源为12 V。对实验过程中的铁离子浓度在阴阳两极出水实时变化趋势进行定量分析，得出结论：实验设备可使Fe2+向Fe3+转化，最终向沉淀转化。对实验产物进行定性分析，通过XRD表征可知产物成分为氧化铁，通过SEM表征对氧化铁产物形貌进行分析，可知产物晶体为片状，粒径为纳米，分布较为均匀。并对实验接下来的方向提出要求，制备形貌可控的氧化铁纳米材料，以及再生酸液可达到回用标准。 Waste pickling is a major obstacle to the development of metal building materials industry, and the treatment of waste pickling has become one of the hot topics in recent years in China. In this paper, the treatment process and the experimental samples of simulated waste pickling with Fe2+ concentration of 1 g/L were analyzed by the self-made electrochemical device, and the external power supply was 12 V. The quantitative analysis of the real-time variation trend of ferric ion concentration in cathode and anode during the experiment was carried out. The conclusion is that the experimental equipment can transform Fe2+ to Fe3+ and finally to the precipitation. The quali-tative analysis of the experimental products showed that the samples were iron oxide by XRD, and the pattern of iron oxide was analyzed by SEM. It was found that the crystal samples was flaky, the particle size was nanometer, and well-distributed. In addition, the requirements of the following experiments were proposed to prepare the iron oxide nano-materials with controllable pattern, and the regenerated acid could be reused.

Feasibility Study of Using Radio-frequency Identification Technology in Estimating the Time Pattern of Exposure to Causative Agents of Occupational Diseases.

Background:At workplaces, the workers exposed to several harmful agents such as physical, chemical, and biological pollutant that cause occupational diseases. There are a lot of jobs that not allow a certain pattern of exposure to this agent. In this article, we introduce a technology named radio-frequency identification (RFID) to estimate the exposure time of workers to harmful agent.Materials and Methods:This applied study was carried out experimentally in an industry in Isfahan province, Iran. Twenty-nine participants selected from the workers without a fixed pattern of exposure. Two methods used to measure the exposure time of them. The first method was based on a self-made RFID device and conducted by the workers. The second method performed by stopwatch, which was carried out by the occupational hygienist. The results were analyzed using SPSS 20 and descriptive statistics, Spearman correlation coefficient, and paired samples t-test.Results:The mean age of the participants was 36.48 ± 5.889 and job experience was 9.06 ± 6.316 years. Spearman correlation coefficient shows that there is a significant correlation between the exposure times measured by the workers and occupational hygienist (R in all zones was higher than 0.9, P < 0.05). Paired samples t-test shows that there are no significant differences between the mean exposure times measured by the workers and occupational hygienist in each zone and in all the zones (P > 0.05).Conclusion:RFID technology is an appropriate method to evaluate the exposure time of workers without fixed pattern of exposure to causative factors of occupational diseases. It can also be used in other fields of occupational health engineering.

Effect of microperc for treatment of renal calculi with self-made optical puncture needle combined with ureteral access sheath

Objective To evaluate the effect of micropercutaneous nephrolithotomy(microperc) for treatment of renal calculi with self-made F 4.8 optic puncture needle combined with ureteral access sheath. Methods There were 23 patients undergoing microperc with the self-made device from June 2016 to April 2017, Male, 12 cases, female, 11 cases. The mean±SD (range) patient age was (49±14) years( 28-67 years), stone volume was (1.7±0.6) cm(1.0-3.0 cm) and stone density was (934.5±282.7) HU(357-1 500 HU). The self-made all-seeing system consists of a puncture needle (F4.85) and two 3-way connector allowing the insertion of a flexible microoptic system, laser fiber and attaching to irrigation system. Single tract with one puncture with ultrasound guide was fit to treat the calices containing calculi or calices at one stage operation. The course of puncture could be all-see on the display which was connected with flexible microoptic system. After stone fragmentation, the procedure was terminated in tubeless fashion. Ureteral double J stent was inserted in order to prevent postoperative complications. The factors analysed were demographic variables including age, sex, stone volume, stone density [Hounsfield units (HU)] and stone location, and intra- and peri-operative variables such as operating time, drop in haemoglobin level, stone clearance and complications. Results Conversion to PCNL was required in one patient because intraoperative bleeding obscured vision. The mean±SD(range) operation duration was (46.2±19.9) min(20-120 min), pain score was 2.8±1.2(1-6), hemoglobin decrease was 6.6 g/L, and in hospital time was (2.9±0.8) d(2-5 d) , respectively. No patient required blood transfusion. Stone-free rate at 1 and 3 months postoperation was 90.9%(20/22) and 100 %(22/22), respectively. Two who suffered hematuria(Clavien Ⅰ)underwent conservative treatment and recorered well. One suffered urinary tract infections(ClavienⅡ) and was treated with antibiotics. There were no major complications. Conclusions Mircoperc with the self-made device and ureteral access sheath in management of renal calculi is feasible and effective. Key words: Micropercutaneous nephrolithotomy; Optical puncture needle; Ureteral access sheath; Renal calculi; Percutaneous nephrolithotripsy

Probabilistic Approach to Robust Wearable Gaze Tracking.

This paper presents a method for computing the gaze point using camera data captured with a wearable gaze tracking device. The method utilizes a physical model of the human eye, advanced Bayesian computer vision algorithms, and Kalman filtering, resulting in high accuracy and low noise. Our C++ implementation can process camera streams with 30 frames per second in realtime. The performance of the system is validated in an exhaustive experimental setup with 19 participants, using a self-made device. Due to the used eye model and binocular cameras, the system is accurate for all distances and invariant to device movement. We also test our system against a best-in-class commercial device which is outperformed for spatial accuracy and precision. The software and hardware instructions as well as the experimental data are published as open source.

Determination of Migration of Six Phthalate Esters in Plastic Toys by GC-MS/MS Coupled with Solid-Phase Extraction Using Cucurbit[n]urils as Adsorbent

Object: This paper presents a method for the determination of migration of six phthalate esters in plastic toys based on gas chromatography-tandem mass spectrometry (GC-MS/MS) coupled with solid phase extraction using cucurbiturils (CB6-8) as adsorbent. Method: On the base of self-made migration device, toy samples were migrated for 10 min to 24 h in simulated saliva at 37 °C. The analytes were adsorbed by cucurbiturils SPE cartridges, eluted with ethyl acetate, then determined by GC-MS/MS and quantified by external standard method. The eluting solvents as well as the type and amount of the extraction materials were carefully optimized, then the reusability of the SPE cartridges was investigated. The limits of quantification (LOQs) ranged from 2.5 µg/L to 12.5 µg/L. Average recoveries of target analytes (spiked at three concentration levels) were in the range of 82.7% to 94.4%. Intraday repeatability and interday repeatability of the method varied from 2.3% to 6.6% and from 5.6% to 10.8%, respectively. Conclusion: The proposed method was finally used to explore the migration behavior of phthalate esters in commercial plastic toys.