Effect of Paint Exposure Among Paint Workers and DNA Damage: A Scoping Review

@#Paint contains various complex chemical mixtures, such as aliphatic hydrocarbons, aromatic hydrocarbons (primarily toluene), ketones, and benzene as reported at previous studies. Toxicity from some chemicals can cause early DNA damage with various factors. A scoping review was conducted via literature review on relevant studies on the effect of paint exposure on paint workers and DNA damage. A systematic search was conducted in October 2021 via PubMed, Scopus, and Web of Science databases. The key terms used were paint, solvent-based paint, organic solvent, mixed organic solvent, occupational exposure and DNA damage, oxidative stress, genotoxicity on a painter, paint worker. From 561 articles, only 13 articles were finally selected based on the inclusion, exclusion criteria, and eligibility criteria. The literature showed that biomonitoring studies on painters were consistently reporting positive and significant DNA damage due to exposure to different types of compounds mixed in a paint. However, there were fewer studies on paint manufacturing factory workers compared to painters while paint manufacturing workers exposed various chemical everyday during the paint production which potentially susceptible to occupational toxicity. In conclusion, this review suggests that exposure to paints could induce early DNA damage among paint workers and further investigations on paint exposure among paint manufacturing factory workers and the DNA damage were needed in order to improve occupational health among paint workers in the future.

Analyzing the prevalence of key occupational hazards in 56 printing enterprises in Shenzhen City / 中国职业医学

@# Objective To investigate the prevalence of the occupational hazard of organic solvent and noise in printing and Methods record medium production enterprises in Longgang District of Shenzhen City. A total of 56 printing and record medium production enterprises were selected as the study subjects by judgmental sampling method to analyze the worksite Results survey of occupational health and the key occupational hazard factors. There were 256 organic solvent samples ， detected in 56 enterprises which included a total of 148 terms and 1 358 categories of volatile constituents. The top three （ ）， - （ ） （ ） volatile constituents were toluene 35.5% n hexane 25.7% and methanol 23.8% . The top three detected samples of the （ ， ， ， ， - ， ，- ， eight key chemical occupational hazard factors benzene toluene xylene ethylbenzene n hexane 1 2 dichloroethane ） ， - ， trichloroethylene and chloroform were toluene n hexane and ethylbenzene. In the workplace air toluene was the most risk ， factor of occupational hazard factors in enterprise and in sample detection while no trichloromethane was detected. The toluene in workplace air was found to exceed the national standard with the rate of 2.6%. It showed that 27.9% of the work sites were found occupational noise hazard which was over national standard in the 10 key work sites. Only 64.3% and 57.1% enterprises - performed occupational hazard factors detection and occupational health examination. Both none or invalid toxicant proof - facilities accounted for 33.9% of the enterprises. Both none or invalid noise proof facilities accounted for 78.6% of the Conclusion ， - enterprises. The occupational hazards factor of toluene n hexane and noise were serious in printing and record ， medium production enterprises in Longgang District of Shenzhen City and the occupational health management was imperfect. The occupational regulation should be enhanced in this industry.

A case of acute organic solvent poisoning during epoxy coating

BACKGROUND: In the construction industry, maintaining health and safety of workers often challenging. Among the workers at construction sites, painters are at particular risk of respiratory diseases and neurotoxicity. However, in Korea there is weak enforcement of workers' health and safety practices in the construction industry in Korea. Poisonings frequently occur at (semi)closed construction sites. In this study, we report a case of acute organic solvent poisoning during construction site painting. CASE PRESENTATION: A 71-year-old man was found unconscious at a construction site and immediately transferred to the emergency room. The consciousness level was 'stupor state' and the body temperature was hypothermic, at 32 degrees (Celsius). There were no acute brain or cardiac lesions that would have accounted for the faintness. In addition, blood and urine tests did not indicate a cause of loss of consciousness. He had been painting epoxy to waterproof the basement floor before fainting. According to exposure simulation, the patient was overexposed to various organic solvents, such as approximately 316–624 ppm toluene during the work before fainting. Considering the ventilation status of the workplace and the status of no protection, it is considered that exposure through the respiratory tract was considerable. CONCLUSIONS: The patient in this case lost consciousness during the epoxy coating in a semi-enclosed space. It can be judged as a result of acute poisoning caused by organic solvent exposure and considered to be highly related to work environment.

Growth study of organic solvent tolerant bacteria (OSTB) in solvent waste mixture of semiconductor industry

@#Aims:Increasing of organic solvent waste contributed as one of the most critical environmental problems. Huge amount of solvents hasbeen applied in the industrial process, but it is not followed by a good waste treatment. Up to our knowledge only a few studieshas been conducted in applying the biological treatment on the solvent waste mixtures specifically by Gram’s positive organic solvent tolerant bacteria (OSTB). The study aims to identify the ability of OSTB survival in solvent waste mixture of the semiconductor industry in comparison to synthetic organic solvent by OSTB inoculation.Methodology and results:Strain of OSTB named as Bacillus subtilis, BSIAs was applied in the study. The growth of this OSTB in different concentration of synthetic solvent isopropyl alcohol (IPA) and in actual solvent waste mixture consists of IPA was monitored and measured. There are three different concentrations (v/v) of synthetic solvent IPA was used as a media that are 20%, 10% and 5% for testing the growth of B.subtilisBSIAs. The 5% concentration of IPA was suitable for B.subtilisBSIAs growth. After 14 hof growth, distillation process was used to separate the remaining solvent from the mixture. It was found that, the volume after biological treatment was reduced by 1 mL from the initial volume of solvent before the biological treatment. This OSTB also utilized solvent in 1% concentration of real solvent waste mixture within 120 h.Conclusion, significance and impact of study:As a conclusion, the findings reveal that the strain of Gram-positive B.subtilis,BSIAs has the ability to utilize synthetic organic solvent (IPA)and the solvent waste mixture from the semiconductor industry as their carbon sources. The selected OSTB can be considered as bio-agents in the industrial waste management pertaining to solvent waste problems thru green technology approaches.

A new isolate of thermophilic and organic solvent tolerant bacteria for lipase production using basal medium of palm kernel cake 80-87

@#Aims: This research focused on the selection of potential strains especially bacteria that can grow effectively in palm kernel cake (PKC) and produce high amount of thermostable and solvent tolerant (TS-OST) lipase. The work involved the exploration of renewable PKC as potential fermentation medium for discovery to novel TS-OST lipase that would have excellent tolerance and activity in presence of organic solvents with high temperatures for industrial applications.Methodology and results: Using palm kernel cake (PKC) as source of thermophilic bacteria, 53 bacterial strains were found survived at temperature 65 °C. However, after subcultured several times, only 17 strains were found as pure thermophilic strains. Preliminary screening both qualitative and quantitative was performed to all 17 potential thermophilic bacterial strains and showed that only 11 purified thermophilic strains are lipase producer. Strain PKC-P1 produced highest enzyme activity (11.13 U/g), followed by PKC-P13 and PKC-C9. The lowest enzymeactivity was lipase produced byPKC-C10 (0.76U/g). Strain PKC-P1 has been classified as Gram negative bacteria and identified as Bacillus smithiistrain PKC_P1.Conclusion, significance and impact of study: PKC as a by-product of oil palm industry consistsof many nutrients that can give benefits towards industry and can be utilized in order to produce enzymes like lipases. From these results, it could be concluded that this lipase stable at temperature 65 °C and pH 7 and may be a potential candidate to be used in a variety of biotechnological applications. This finding revealed that a bacterial strain obtained from oil-rich environment which is PKC through isolation process has potential as a source of more economical enzyme to be applied in biotechnology industr

Simultaneous Determination of 6 Residual Organic Solvents in Xingnaojing Injection by Headspace GC / 中国药房

OBJECTIVE:To establish the method for simultaneous determination of 6 residual organic solvents in Xingnaojing injection,such as methanol,ethanol,isopropanol,n-butanol,ethyl acetate and acetonitrile.METHODS:Headspace GC method was adopted.The determination was performed on DB-624 capillary column by temperature programming with the injector temperature of 200 ℃;flame ionization detector was adopted with the temperature of 250 ℃;carrier gas was nitrogen with flow rate of 25 mL/min and split ratio of 35 ∶ 1;headspace sampling size was 1 mL,and heating temperature of headspace sampling was 80 ℃;equilibrium time was 15 min.RESULTS:The linear ranges of methanol,ethanol,isopropanol,n-butanol,ethyl acetate and acetonitrile were 15.00-240.00 μg/mL (r =0.999 9),25.00-400.00 μg/mL (r =0.999 9),25.00-400.00 μg/mL (r =0.999 9),25.00-399.99 μg/mL(r=0.999 9),25.00-399.99 μg/mL(r=0.999 8) and 5.00-80.00 μg/mL(r=0.999 9).The LOQ were 5.98,3.94,2.05,2.13,1.39,1.24 μg/mL,and the LOD were 2.01,2.11,1.18,1.56,1.15,0.01 μg/mL,respectively.RSDs of precision tests were all less than 2.0％,stability and repetitive tests only ethyl acetate was detected,RSD＜2.0％;the recoveries were 93.59％-99.02％ (RSD=2.62％,n=6),92.42％-98.40％ (RSD=2.43％,n=6),94.81％-104.64％ (RSD=3.47 ％,n=6),94.56％-106.73％ (RSD=4.21％,n=6),97.04％-106.33％(RSD=3.50％,n=6)and 98.40％-107.97％ (RSD=3.37％,n=6).CONCLUSIONS:The method is specific,rapid,simple and accurate,and can be used for simultaneous determination of 6 residual organic solvents in Xingnaojing injection.

Simultaneous Determination of 6 Residual Organic Solvents in Xingnaojing Injection by Headspace GC / 中国药房

OBJECTIVE:To establish the method for simultaneous determination of 6 residual organic solvents in Xingnaojing injection,such as methanol,ethanol,isopropanol,n-butanol,ethyl acetate and acetonitrile.METHODS:Headspace GC method was adopted.The determination was performed on DB-624 capillary column by temperature programming with the injector temperature of 200 ℃;flame ionization detector was adopted with the temperature of 250 ℃;carrier gas was nitrogen with flow rate of 25 mL/min and split ratio of 35 ∶ 1;headspace sampling size was 1 mL,and heating temperature of headspace sampling was 80 ℃;equilibrium time was 15 min.RESULTS:The linear ranges of methanol,ethanol,isopropanol,n-butanol,ethyl acetate and acetonitrile were 15.00-240.00 μg/mL (r =0.999 9),25.00-400.00 μg/mL (r =0.999 9),25.00-400.00 μg/mL (r =0.999 9),25.00-399.99 μg/mL(r=0.999 9),25.00-399.99 μg/mL(r=0.999 8) and 5.00-80.00 μg/mL(r=0.999 9).The LOQ were 5.98,3.94,2.05,2.13,1.39,1.24 μg/mL,and the LOD were 2.01,2.11,1.18,1.56,1.15,0.01 μg/mL,respectively.RSDs of precision tests were all less than 2.0％,stability and repetitive tests only ethyl acetate was detected,RSD＜2.0％;the recoveries were 93.59％-99.02％ (RSD=2.62％,n=6),92.42％-98.40％ (RSD=2.43％,n=6),94.81％-104.64％ (RSD=3.47 ％,n=6),94.56％-106.73％ (RSD=4.21％,n=6),97.04％-106.33％(RSD=3.50％,n=6)and 98.40％-107.97％ (RSD=3.37％,n=6).CONCLUSIONS:The method is specific,rapid,simple and accurate,and can be used for simultaneous determination of 6 residual organic solvents in Xingnaojing injection.

Simultaneous Determination of 6 Residual Organic Solvents in Omeprazole Magnesium by Headspace GC / 中国药房

OBJECTIVE:To establish a method for the simultaneous determination of 6 kinds of residual organic solvents in Omeprazole magnesium,such as methanol,isopropanol,acetonitrile,dichloromethane,ethyl acetate and toluenein. METHODS:Headspace GC was adopted. The determination was performed on the column of DB-624 column by temperature programming. The inlet temperature was 200 ℃,and hydrogen flame ionization detector was adopted with the temperature of 250 ℃;nitrogen gas was used as carrier gas with flow rate of 2.0 mL/min;the splitting-radio was 5 : 1,and sample size was 1 mL;the headspace tem-perature was 80 ℃ and the equilibrium time was 20 min. RESULTS:The linear range were 12.56-628.00 μg/mL for methanol(r=0.9997),20.22-1011.20 μg/mL for isopropanol(r=0.9999),1.96-97.76 μg/mL for acetonitrile(r=0.9997),3.10-154.88 μg/mL for dichloromethane(r=0.9998),20.69-1034.56 μg/mL for ethyl acetate(r=0.9998),and 3.53-176.72 μg/mL for toluene(r=0.9998);the limits of quantitation were 1.00,0.91,0.47,0.93,0.41 and 0.35 μg/mL respectively;the limits of detection were 0.31,0.30,0.14,0.31,0.12 and 0.11 μg/mL respectively;RSDs of precision,stability and reproducibility tests were lower than 3%;the recoveries were 94.53%-101.29%(RSD=2.15%,n=9),97.78%-103.42%(RSD=1.77%,n=9),96.99%-105.76%(RSD=2.59%,n=9),96.83%-102.05%(RSD=1.86%,n=9),97.98%-101.13%(RSD=0.88%,n=9)and 97.80%-102.40%(RSD=1.41%,n=9). CONCLUSIONS:The method is sensitive and accurate,can be used for the simultaneous determination of 6 kinds of residual organic solvents in Omeprazole magnesium,such as methanol,isopropanol,acetonitrile,dichloromethane,eth-yl acetate and toluenein.

Simultaneous Determination of 6 Residual Organic Solvents in Aprepitant Raw Material by Headspace Capillary GC / 中国药房

OBJECTIVE:To establish a method for simultaneous determination of 6 residual organic solvents in aprepitant raw material as methanol,ethanol,acetone,isopropyl alcohol,methyl tert-butyl ether and tetrahydrofuran.METHODS:Headspace capillary gas chromatography was adopted.The determination was performed on DB-624 capillary column using temperature programming.The temperature of injector port was 180 ℃,and flame ionization detector was used with temperature of 260 ℃.Nitrogen was used as carrier gas with flow rate 3.0 mL/min.The spilt ratio was 5 ∶ 1,and head-space injection volume was 1.0 mL.The head-space equilibrium temperature was set at 80 ℃,and equilibrium time was 40 min.RESULTS:The linear ranges of methanol,ethanol,acetone,isopropyl alcohol,methyl tert-butyl ether,tetrahydrofuran were 6.052-605.232 μ g/mL (r=0.999 9),9.987-998.718 μg/mL(r=0.999 9),9.998-999.768 μg/mL(r=0.999 8),9.986-998.634 μg/mL(r=0.999 9),9.991-999.090 μg/mL (r=0.999 7),1.461-146.133 μg/mL(r=0.999 5),respectively.The limits of quantitation were 1.782 1,2.079 0,0.749 8,1.777 8,0.223 1,0.607 0 μg/mL;the limits of detection were 0.594 0,0.693 0,0.249 9,0.592 6,0.074 4,0.202 3 μg/mL,respectively.RSD of precision test was lower than 2.0％.Only acetone and isopropyl alcohol were detected in stability test and reproducibility tests,RSD＜2.0％.Their recoveries were 99.34-100.75％ (RSD=0.52％,n=9),98.20％-100.24％ (RSD=0.69％,n=9),98.07％-100.07％ (RSD=0.84％,n=9),99.86％-101.32％ (RSD=0.58％,n=9),97.87％-104.02％ (RSD=2.13％,n=9),98.26 ％-100.58 ％ (RSD =0.75 ％,n =9),respectively.CONCLUSIONS:The established method is simple,accurate and reproducible,and can be used for simultaneous determination of 6 residual organic solvents in aprepitant raw material.

Determination of Residual Organic Solvents in Piperazine Ferulate by GC / 中国药师

Objective:To establish a method for the determination of benzene, chlorine alcohol and pyridine residues in piperazine ferulate. Methods:GC was used with a DB-624 (30 m × 0. 53 mm, 1. 0 μm) elastic quartz capillary column. The flame ionization detector was used with nitrogen as the carrier gas. The initial temperature was 50℃, maintaining for 5 min, and raised to 80℃ at the rate of 10℃·min-1 , and then raised to 200℃ at the rate of 50℃·min-1 , and maintaining for 4 minutes. The inlet temperature was 200℃, and the detector temperature was 220℃. The split ratio was 1 ∶1 and the injection volume was 1μl. The flow rate was 3 ml· min-1. Results:The linear range of benzene was 0.16-0.96 μg·ml-1(r=0.999 5), the average recovery was 95.7% (RSD =2.1, n=9), and the detection limit was 0.16 ng. The linear range of chlorine alcohol was 16.11-96.65 μg·ml-1(r=0.999 7), the average recovery was 97. 8% (RSD=2. 1, n=9), and the detection limit was 0. 62 ng. The linear range of pyridine was 15. 87-95. 23 μg·ml-1(r=0. 999 8), the average recovery was 99. 2% (RSD=1. 3, n=9), and the detection limit was 0. 15 ng. Con-clusion:The method is reliable, simple, accurate and stable, and suitable for the determination of benzene, chlorine alcohol and pyri-dine residues in piperazine ferulate.

Simultaneous Determination of 8 Residual Organic Solvents in Esomeprazole Magnesium Raw Material by Capillary GC / 中国药房

OBJECTIVE:To develop a method for simultaneous determination of 8 residual organic solvents in esomeprazole magnesium raw material,including ethanol,ethyl acetate,isopropylenzene,methanol,methylbenzene,2-phenyl-2-propanol,dichloromethane and acetonitrile.METHODS:Capillary GC was adopted.The determination was performed on HP-1 column by programmed temperature.The temperature of injector port was 220 ℃,with flame ionization detector at temperate of 250 ℃,using nitrogen as carrier gas,at the flow rate of 4.0 mL/min,with split ratio of 10∶1 and injection volume of 1 μL.RESULTS:The linear ranges of ethanol,ethyl acetate,isopropylenzene,methanol,methylbenzene,2-phenyl-2-propanol,dichloromethane and acetonitrile were 45.2-904 μg/mL(r=0.999 7),45.5-909 μg/mL(r=0.999 7),9.0-180 μg/mL(r=0.999 8),27.1-542 μg/mL(r=0.999 8),8.7-174 μg/mL(r=0.999 7),9.1-183 μg/mL(r=0.999 4),5.8-115 μg/mL(r=0.999 4),3.7-74 μg/mL(r=0.999 4),respectively.The quantitation limits were 4.5,3.0,1.4,2.7,0.6,3.0,3.9,2.8 ng,and the limits of detection were 2.2,1.0,0.4,1.4,0.3,1.0,2.0,1.4 ng,respectively.RSDs of precision tests were all lower than 2.0％.Only ethanol,methanol and methylbenzene were detected in reproducibility test,RSDs of their peak area were lower than 2.0％.The recoveries were 95.6％-104.9％ (RSD=3.3％,n=9),98.7％-102.0％ (RSD=1.1％,n=9),100.0％-103.1％ (RSD=1.1％,n=9),95.7％-104.4％ (RSD=3.0％,n=9),99.3％-104.4％ (RSD=1.7 ％,n=9),95.6％-102.2％ (RSD=2.6％,n=9),95.1％-103.3％ (RSD=2.6％,n=9),97.5％-103.3％ (RSD =1.7 ％,n =9),respectively.CONCLUSIONS:The method is sensitive and simple,and it is suitable for simultaneous determination of 8 residual organic solvents in esomerarazole magnesium raw material.

Determination of 7 Residual Organic Solvents in Shengxuening Tablets by Headspace Gas Chromatography / 中国药师

Objective:To establish a method for the determination of 7 residual organic solvents including acetone,2,3 -dimethyl-pentane,3-methylhexane,n-heptane,2,2-dimethylhexane,o-xylene and 2,4,6-trimethylpyridine in Shengxuening tablets. Methods: A headspace gas chromatography method was adopted. The determination was performed on a DB-5MS capillary column ( 30 m × 0. 25 mm,0. 25 μm) with programming temperature. Nitrogen was used as the carrier gas at the flow rate of 2. 5 ml·min-1 . The tem-perature of injector was 200℃,and a flame ionization detector was used as the temperature of 250℃. The containers of headspace in-jector were in equilibrium at 95℃ for 30min. DMF was used as the solvent and an external standard method was used for the determi-nation of the 7 residual solvents. The injection volume was 1 ml. Results:Under the chromatographic conditions, the 7 residual organic solvents could be well separated from each other . The concentration of each solvent showed a good linearity with the peak area within the investigated concentration range (r≥0. 994 4). The average recoveries were 98. 72%-99. 71% (RSD=0. 14%-0. 71%)(n=9). Conclusion:The established method is simple, rapid and sensitive, which can be used for the determination of multiple residual or-ganic solvents in Shengxuening tablets.

Simultaneous Determination of 6 Organic Solvents in Tosufloxacin Tosylate by Headspace GC / 中国药房

OBJECTIVE:To establish a method for the residual simultaneous determination of methanol,alcohol,dichlorometh-ane,n-hexane,tetrahydrofuran and benzene in tosufloxacin tosylat. METHODS:Headspace GC was performed on the capillary col-umn with 6%cyanopropylphenyl-94%dimethylpolysiloxane(DB-624)as fixative lipid,temperature programmed,the inlet temper-ature was 180 ℃,detector was flame ionization detector with temperature of 300 ℃,carrier gas was high purity N2 at a flow rate of 1.5 mL/min,split ratio was 10:1,headspace equilibrium temperature was 100℃,equilibrium time was 40 min,headspace sam-ple volume was 10 mL,and the headspace sample volume was 1 mL. RESULTS:The linear range was 178.3-1782.7 μg/mL for methanol (r=0.9991),301.2-3012.1 μg/mL for alcohol(r=0.9997),33.81-338.10 μg/mL for dichloromethane(r=0.9993), 18.02-180.22 μg/mL for n-hexane(r=0.9991),43.26-432.58 μg/mL for tetrahydrofuran(r=0.9991)and 0.1268-1.2681 μg/mL for benzene(r=0.9991);limits of quantification were 0.31,3.00,0.67,0.02,0.005,0.10 μg/mL,limits of detection were 0.15, 1.51,0.22,0.01,0.001,0.05 μg/mL;RSD of precision test was no higher than 3.1%;RSDs of methanol and n-hexane in stabili-ty and reproducibility tests were no higher than 5%;recoveries were 93.72%-102.20%(RSD=3.1%,n=9),90.10%-101.79%(RSD=4.0%,n=9),97.07%-103.11%(RSD=2.0%,n=9),92.38%-103.83%(RSD=3.9%,n=9),95.44%-103.62%(RSD=2.8%,n=9),and 94.00%-104.73%(RSD=4.1%,n=9). CONCLUSIONS:The method is rapid,sensitive,accurate,and suitable for the residual determination of methanol,alcohol,dichloromethane,n-hexane,tetrahydrofuran and benzene in tosufloxacin tosylat.

Influencing factors on usage of personal protective equipment in migrant workers exposed to organic solvent / 中国职业医学

OBJECTIVE: To observe the correct use of personal protective equipment( PPE) in migrant workers exposed to organic solvent,and to analyze the influencing factors. METHODS: A total of 108 migrant workers engaged in organic solvents working in the small and medium-sized enterprises were selected as study subjects by judgment sampling method.A self-designed questionnaire was used to investigate their PPE utilization status. In addition,the influcing factors on the effective usage of PPE were analyzed. RESULTS: There were 52. 8% of migrant workers exposed to organic solvent who use the PPE correctly in their work. The multiple logistic regression analysis showed that the higher the average monthly income,the greater the possibility of using the PPE correctly( P < 0. 05). The more frequent the number of respiratory tract infections in the past 6 months,the less likely the PPE was used correctly( P < 0. 05). The co-workers or supervisor often urge the use of PPE and co-workers use PPE correctly when exposed to organic solvent play a role in promoting the right usage of PPE in migrant workers( P < 0. 05). CONCLUSION: The correct use of PPE in migrant workers exposed to organic solvent is still needed to be improved. The peer education and improvement of enterprises' occupational health management are considered as important measures to promote the proper use of PPE in migrant workers exposed to organic solvent.

Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07

ABSTRACT The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 ºC and pH 7, using a 0.5% (v/v) inoculum, 2% (v/v) castor oil (inducer), and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 ºC and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax) revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.

Enhanced production and organic solvent stability of a protease fromBrevibacillus laterosporus strain PAP04

A bacterial strain (PAP04) isolated from cattle farm soil was shown to produce an extracellular, solvent-stable protease. Sequence analysis using 16S rRNA showed that this strain was highly homologous (99%) to Brevibacillus laterosporus. Growth conditions that optimize protease production in this strain were determined as maltose (carbon source), skim milk (nitrogen source), pH 7.0, 40°C temperature, and 48 h incubation. Overall, conditions were optimized to yield a 5.91-fold higher production of protease compared to standard conditions. Furthermore, the stability of the enzyme in organic solvents was assessed by incubation for 2 weeks in solutions containing 50% concentration of various organic solvents. The enzyme retained activity in all tested solvents except ethanol; however, the protease activity was stimulated in benzene (74%) followed by acetone (63%) and chloroform (54.8%). In addition, the plate assay and zymography results also confirmed the stability of the PAP04 protease in various organic solvents. The organic solvent stability of this protease at high (50%) concentrations of solvents makes it an alternative catalyst for peptide synthesis in non-aqueous media.

Determination of Residual Solvents in Faeces Bombycis Extract by GC / 中国药师

Objective:To establish a method for the determination of solvent residues in faeces bombycis extract by GC .Meth-ods: A GC-headspace injection method was adopted to detect the residual organic solvents in the extract of faeces bombycis .A DB-5MS (30 m ×0.25 mm ×0.25 μm) quartz capillary column was used as the chromatographic column;nitrogen was used as the carrier gas at a flow rate of 0.6 ml· min-1;the injector temperature was 200℃;the detector was a flame ionization detector( FID) with the temperature of 250℃;the temperature program included two phases:the initial temperature was set at 40℃for 10 min, and then risen to 200℃at a rate of 5℃· min-1 and maintained for 5 min;the equilibrium temperature of headspace was 95℃;the equilibrium time was 30 min;the capillary temperature was 110℃;the injection ring temperature was 125℃.Results:The linear range of acetone , 2, 3-dimethylpentane, 3-methylhexane, heptane, 2,2-dimethylhexane, p-xylene, m-xylene, O-xylene and 2,4,6-collidine was 101-3 034μg· ml-1 , 100-2 995 μg· ml-1 , 107-3 197 μg· ml-1 , 101-3 019 μg· ml-1 , 99-2 962 μg· ml-1 , 45-1 358 μg· ml-1 , 44-1 325μg· ml-1, 47-1 411 μg· ml-1 and 104-3 130 μg· ml-1, respectively, and the average r was all above 0.992.The recovery of the method met the requirement , and the blank solvent showed no interference .Eight samples were all accordance with the requirements after the examination .Conclusion:The headspace injection method for the determination of residual organic solvents in the extract of faeces bombycis is simple and reliable .

Determination of Residual Organic Solvents in Trepibutone by Headspace Gas Chromatography / 医药导报

Objective To establish a headspace GC method for determination of residual organic solvents as methanol, ethanol,dichloromethane and n-hexane in trepibutone. Methods An external standard method was used. A DB-624 capillary column (75 m× 0.450 mm,2.55 μm) was used with a FID detector. The injector temperature was 200 ℃ and the detector temperature was 250 ℃ .The initial column temperature was 50 ℃ ,kept for 6 min,then raised to 200 ℃ at a rate of 20 ℃ ?min-1 and kept for another 12 min. Nitrogen was used as the carrier gas. The flow rate was 3. 0 mL ? min-1 . The headspace vials equilibrium temperature was 80 ℃ and the balance time was 30 min.The injection volume is 1 mL. Results A1l the solvents could be completely separated with good linear relationships.The average recoveries of the four solvents were 100.4% ( RSD =0.5%), 100.6%(RSD = 0.6%), 99.6% ( RSD = 0.8%), 98.7% ( RSD = 0.7%) ( n = 9),respectively. Conclusion The method is simple and accurate,and can be used in the determination of residual solvents in trepibutone.

IgA nephropathy in a laboratory worker that progressed to end-stage renal disease: a case report

BACKGROUND: IgA nephropathy (IgAN) is the most common form of glomerulonephritis, a principal cause of end-stage renal disease (ESRD) worldwide. The mechanisms of onset and progression of IgAN have not been fully revealed, and epidemiologic studies have yielded diverging opinions as to the role of occupational exposure to organic solvents in the initiation or worsening of IgAN. As the authors encountered a laboratory worker with IgAN that progressed to ESRD, we present a case report of IgAN progression due to dichloromethane exposure along with a review of literature. CASE PRESENTATION: A 41-year-old male laboratory worker began to experience gross painless hematuria after two years of occupational exposure to toluene. Although clinical follow-up was initiated under the impression of IgAN based on clinical findings, the patient continued to work for four more years in the same laboratory, during which he was in charge of laboratory analysis with direct exposure to a high concentration of dichloromethane without proper protective equipment. During that time, his renal function rapidly worsened and finally progressed to ESRD 10 years after the first clinical symptoms. The result of exposure assessment through reenactment of his work exceeded the occupational exposure limit for dichloromethane to a considerable degree. CONCLUSIONS: The causal association between occupational solvent exposure and IgAN is still unclear; therefore, this case report could be used as a basis to support the relevance of occupational solvent exposure to IgAN and/or its progression. Early intervention as well as close monitoring of laboratory workers exposed to various organic solvents is important to prevent or delay the progression of glomerulonephritis to ESRD in the occupational setting.

Determination of Eight Residual Organic Solvents in Tolterodine Tartrate by Capillary Gas Chromatography / 中国药师

Objective:To establish a method for the determination of 8 residual organic solvents in tolterodine tartrate by capillary GC. Methods: The determination of methanol, ethanol, acetonitrile, acetone, ethyl acetate, trichloromethane and tetrahydrofuran in tolterodine tartrate dissolved in the solution of N, N-dimethylformamide-water ( 1∶ 4 ) was carried out on a CP-sil 5CB ( 60. 0 m × 0. 32 mm,5μm)column. The inlet temperature was 200℃ and the FID detector temperature was 250℃. The flow rate of carrier gas was 1. 2 ml·min-1 . The column temperature was 120℃. The headspace vial temperature was 85℃ and the time was 30min. The determina-tion of pyridine in tolterodine tartrate dissolved in the solution of dimethylsulfoxide-sodium hydroxide (17∶13) was carried out on an HP-1(30. 0 m × 0. 53 mm,5 μm) column. The inlet temperature was 220℃ and the FID detector temperature was 250℃. The column tem-perature was 80℃. The flow rate of carrier gas was 3. 0 ml·min-1 . The headspace vial temperature was 85℃ and the time was 30 min. Results:All peaks could be separated from each other under the chromatographic conditions. The linearity of the eight solvents was falrly good (r>0. 999). The average recovery was ranged from 86. 0% to 100. 2% with RSD of 1. 7%-3. 5% (n=9). The limit of detection was 0. 63, 0. 43, 0. 30, 0. 18, 0. 079, 0. 36, 0. 18 and 0. 89 μg·ml-1 , respectively. Conclusion:The methods can be applied in the determination of the eight residual organic solvents in tolterodine tartrate.