Quantifying drivers of variability in life cycle greenhouse gas emissions of consumer products—a case study on laundry washing in Europe

Purpose

Variability in consumer behaviour can significantly influence the environmental performance of products and their associated impacts and this is typically not quantified in life cycle assessments. The goal of this paper is to demonstrate how consumer behaviour data can be used to understand and quantify the variability in the greenhouse gas emissions from domestic laundry washing across Europe.

Methods

Data from a pan-European consumer survey of product usage and washing habits was combined with internal company data on product format greenhouse gas (GHG) footprints and in-home measurement of energy consumption of laundry washing as well as literature data to determine the GHG footprint of laundry washing. The variability associated with four laundry detergent product formats and four wash temperature settings in washing machines were quantified on a per wash cycle basis across 23 European countries. The variability in GHG emissions associated with country electricity grid mixes was also taken into account. Monte Carlo methods were used to convert the variability in the input parameters into variability of the life cycle GHG emissions. Rank correlation analysis was used to quantify the importance of the different sources of variability.

Results and discussion

Both inter-country differences in background electricity mix as well as intra-country variation in consumer behaviour are important for determining the variability in life cycle GHG emissions of laundry detergents. The average GHG emissions related to the laundry washing process in the 23 European countries in 2014 was estimated to be 5?×?10² g CO_2?eq/wash cycle, but varied by a factor of 6.5 between countries. Intra-country variability is between a factor of 3.5 and 5.0 (90% interval). For countries with a mainly fossil-based electricity system, the dominant source of variability in GHG emissions results from consumer choices in the use of washing machines. For countries with a relatively low-carbon electricity mix, variability in life cycle GHG emissions is mainly determined by laundry product-related parameters.

Conclusions

The combination of rich data sources enabled the quantification of the variability in the life cycle GHG emissions of laundry washing which is driven by a variety of consumer choices, manufacturer choices and infrastructural differences of countries. The improved understanding of the variability needs to be balanced against the cost and challenges of assessing of consumer habits.

     

Sharing is caring - the importance of capital goods when assessing environmental impacts from private and shared laundry systems in Sweden

The International Journal of Life Cycle Assessment - Previous studies on environmental impacts from domestic laundry have tended to focus solely on private washing machines and detergent. However,...     

医院纺织品洗涤质量管理标准化研究

北京协和医院在结合欧洲EN 14065卫生洗涤标准等行业标准的基础上,通过对医院洗衣房的整体规划和改造,积极探索医院纺织品洗涤质量管理标准化。医院洗衣房的建筑布局以隔离式洗衣机为中心进行设计,设置相对独立的污染区和清洁区,遵循纺织品由污染区向清洁区运行的单项流程,减少院内感染的风险。在此基础上完善相关规章制度,以保障洗衣房的正常运行。纺织品洗涤的各个环节均应由经过专业培训的人员按照标准化的流程进行操作,同时需关注工作人员的职业防护,并在保障洗涤质量的前提下减少能源消耗。     

Fate of Escherichia coli O145 present naturally in bovine slurry applied to vegetables before harvest,after washing and simulated wholesale and retail distribution

Aims

To determine the fate of Escherichia coli on vegetables that were processed through commercial wash treatments and stored under simulated retail conditions at 4°C or wholesale at fluctuating ambient temperatures (0–25°C, dependent on season).

Methods and Results

Bovine slurry that was naturally contaminated with E. coli O145 was applied without dilution or diluted 1:10 using borehole water to growing potatoes, leeks or carrots. Manure was applied 1 week prior to harvest to simulate a near‐harvest contamination event by manure deposition or an application of contaminated water to simulate a flooding event or irrigation from a contaminated water source. At harvest, crops were contaminated at up to 2 log cfu g^?1. Washing transferred E. coli into the water of a flotation tank used for potato washing and did not completely remove all traces of contamination from the crop. Manure‐contaminated potatoes were observed to contain 0·72 cfu E. coli O145 g^?1 after processing and retail storage. Manure‐contaminated leeks harboured 0·73–1·55 cfu E. coli O145 g^?1 after washing and storage. There was no cross‐contamination when leeks were spray washed. Washing in an abrasive drum resulted in less than perfect decontamination for manure‐contaminated carrots. There were five post‐distribution isolations from carrots irrigated with contaminated water 24 h prior to harvest.

Conclusions

Standard commercial washing and distribution conditions may be insufficient to reliably control human pathogenic E. coli on fresh produce.

Significance and Impact

Previous speculation that the cause of a UK foodborne disease outbreak was soil from imperfectly cleaned vegetables is plausible.     

Daily variation of oral malodour and related factors in community-dwelling elderly Thai

doi: 10.1111/j.1741‐2358.2011.00593.x Daily variation of oral malodour and related factors in community‐dwelling elderly Thai Objectives: The purposes of this study were (i) to estimate the prevalence of oral malodour, (ii) to evaluate the daily variation of oral malodour and (iii) to assess associations of volatile sulphur compound (VSC) concentrations with socio‐demographics, health behaviours and oral health status in community‐dwelling elderly Thai. Methods: The subjects were 428 dentate elderly people (67.6 ± 5.6 years) living in Phitsaulok, Thailand. Information on their socio‐demographics, general health and health behaviours was obtained by a questionnaire. Their dental condition, periodontal status and tongue coating were clinically examined. Their flow rates and the pH of unstimulated saliva were also assessed. Oral malodour was measured at four different times of day using an Oral Chroma?. Results: The proportions of subjects diagnosed with oral malodour using the thresholds of H₂S, CH₃SH and (CH₃)₂S were 60.5%, 62.9% and 80.7%, respectively. Concentrations of H₂S showed significant daily variation. Linear regression analysis demonstrated the following significant associations: (i) oral malodour from H₂S and thickness of the tongue coating, (ii) oral malodour from CH₃SH and periodontal pocket depth of 5 mm or more and the presence of gingival bleeding and (iii) oral malodour from (CH₃)₂S and systemic disease, medications and thickness of the tongue coating. Discussion: Oral malodour was shown to be prevalent among the elderly. Daily variation was observed in the concentration of H₂S. Tongue coating, periodontal disease, systemic diseases and medications were related to oral malodour. Therefore, these factors should be taken into consideration in oral malodour treatment and prevention programmes for the elderly.     

Effect of Volatile Organic Compounds from Bacteria on Nematodes

The five studied bacterial strains could produce volatile organic compounds (VOCs) that kill nematodes. Based on their 16S rRNA sequences, these strains were identified as Pseudochrobactrum saccharolyticum, Wautersiella falsenii, Proteus hauseri, Arthrobacter nicotianae, and Achromobacter xylosoxidans. The bacterial VOCs were extracted using solid‐phase micro‐extraction (SPME) and subsequently identified by GC/MS analysis. The VOCs covered a wide range of aldehydes, ketones, alkyls, alcohols, alkenes, esters, alkynes, acids, ethers, as well as heterocyclic and phenolic compounds. Among the 53 VOCs identified, 19 candidates, produced by different bacteria, were selected to test their nematicidal activity (NA) against Caenorhabditis elegans and Meloidogyne incognita. The seven compounds with the highest NAs were acetophenone, S‐methyl thiobutyrate, dimethyl disulfide, ethyl 3,3‐dimethylacrylate, nonan‐2‐one, 1‐methoxy‐4‐methylbenzene, and butyl isovalerate. Among them, S‐methyl thiobutyrate showed a stronger NA than the commercial insecticide dimethyl disulfide. It was reported for the first time here that the five bacterial strains as well as S‐methyl thiobutyrate, ethyl 3,3‐dimethylacrylate, 1‐methoxy‐4‐methylbenzene, and butyl isovalerate possess NA. These strains and compounds might provide new insights in the search for novel nematicides.     

Enteric virus survival during household laundering and impact of disinfection with sodium hypochlorite

This study was conducted to determine whether enteric viruses (adenovirus, rotavirus, and hepatitis A virus) added to cotton cloth swatches survive the wash cycle, the rinse cycle, and a 28-min permanent press drying cycle as commonly practiced in households in the United States. Detergent with and without bleach (sodium hypochlorite) was added to washing machines containing sterile and virus-inoculated 58-cm2 swatches, 3.2 kg of cotton T-shirts and underwear, and a soiled pillowcase designed to simulate the conditions (pH, organic load, etc.) encountered in soiled laundry. The most important factors for the reduction of virus in laundry were passage through the drying cycle and the addition of sodium hypochlorite. Washing with detergent alone was not found to be effective for the removal or inactivation of enteric viruses, as significant concentrations of virus were found on the swatches (reductions of 92 to 99%). It was also demonstrated that viruses are readily transferred from contaminated cloths to uncontaminated clothes. The use of sodium hypochlorite reduced the number of infectious viruses on the swatches after washing and drying by at least 99.99%. Laundering practices in common use in the United States do not eliminate enteric and respiratory viruses from clothes. The use of bleach can further reduce the numbers of enteric viruses in laundry.     

A rapid culture independent methodology to quantitatively detect and identify common human bacterial pathogens associated with contaminated high purity water

Background

Water and High Purity Water (HPW) distribution systems can be contaminated with human pathogenic microorganisms. This biocontamination may pose a risk to human health as HPW is commonly used in the industrial, pharmaceutical and clinical sectors. Currently, routine microbiological testing of HPW is performed using slow and labour intensive traditional microbiological based techniques. There is a need to develop a rapid culture independent methodology to quantitatively detect and identify biocontamination associated with HPW.

Results

A novel internally controlled 5-plex real-time PCR Nucleic Acid Diagnostics assay (NAD), was designed and optimised in accordance with Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines, to rapidly detect, identify and quantify the human pathogenic bacteria Stenotrophomonas maltophilia, Burkholderia species, Pseudomonas aeruginosa and Serratia marcescens which are commonly associated with the biocontamination of water and water distribution systems. The specificity of the 5-plex assay was tested against genomic DNA isolated from a panel of 95 microorganisms with no cross reactivity observed. The analytical sensitivities of the S. maltophilia, B. cepacia, P. aeruginosa and the S. marcescens assays are 8.5, 5.7, 3.2 and 7.4 genome equivalents respectively.Subsequently, an analysis of HPW supplied by a Millipore Elix 35 water purification unit performed using standard microbiological methods revealed high levels of naturally occurring microbiological contamination. Five litre water samples from this HPW delivery system were also filtered and genomic DNA was purified directly from these filters. These DNA samples were then tested using the developed multiplex real-time PCR NAD assay and despite the high background microbiological contamination observed, both S. maltophilia and Burkholderia species were quantitatively detected and identified. At both sampling points the levels of both S. maltophilia and Burkholderia species present was above the threshold of 10 cfu/100 ml recommended by both EU and US guidelines.

Conclusions

The novel culture independent methodology described in this study allows for rapid (<5 h), quantitative detection and identification of these four human pathogens from biocontaminated water and HPW distribution systems. We propose that the described NAD assay and associated methodology could be applied to routine testing of water and HPW distribution systems to assure microbiological safety and high water quality standards.

Electronic supplementary material

The online version of this article (doi:10.1186/s12896-015-0124-1) contains supplementary material, which is available to authorized users.     

Microbiological contamination of laboratory mice and rats in Korea from 1999 to 2003.

To survey the microbiological contamination of laboratory mice and rats in Korea during a 5-year period, we monitored animals housed in mouse and rat facilities with either barrier or conventional systems. At barrier and conventional mouse facilities, the most important pathogen identified was mouse hepatitis virus (MHV), while Mycoplasma pulmonis was the most important pathogen at conventional rat facilities. Interestingly, hantavirus was recovered from both barrier and conventional mouse facilities. The most common protozoon identified was Tritrichomonas muris in mouse facilities and Entamoeba muris in rat facilities. In addition, we found that the microbiological contamination of mice and rats in conventional facilities was severe. These results suggest that conventional facilities should be renovated and monitored regularly to decrease microbiological contamination. We also propose that hantavirus should be monitored in Korea as an important mouse pathogen.     

Enteric Virus Survival during Household Laundering and Impact of Disinfection with Sodium Hypochlorite

This study was conducted to determine whether enteric viruses (adenovirus, rotavirus, and hepatitis A virus) added to cotton cloth swatches survive the wash cycle, the rinse cycle, and a 28-min permanent press drying cycle as commonly practiced in households in the United States. Detergent with and without bleach (sodium hypochlorite) was added to washing machines containing sterile and virus-inoculated 58-cm² swatches, 3.2 kg of cotton T-shirts and underwear, and a soiled pillowcase designed to simulate the conditions (pH, organic load, etc.) encountered in soiled laundry. The most important factors for the reduction of virus in laundry were passage through the drying cycle and the addition of sodium hypochlorite. Washing with detergent alone was not found to be effective for the removal or inactivation of enteric viruses, as significant concentrations of virus were found on the swatches (reductions of 92 to 99%). It was also demonstrated that viruses are readily transferred from contaminated cloths to uncontaminated clothes. The use of sodium hypochlorite reduced the number of infectious viruses on the swatches after washing and drying by at least 99.99%. Laundering practices in common use in the United States do not eliminate enteric and respiratory viruses from clothes. The use of bleach can further reduce the numbers of enteric viruses in laundry.     

Sanitation in self-service automatic washers.

The potential for microbial transfer in self-service laundry washing machines was investigated by obtaining swab samples from the interior surfaces of commercial machines and wash water samples before and after disinfectant treatment. Three disinfectants (chlorine, a quaternary ammonium product, and a phenolic disinfectant) were used. Four self-service laundry facilities were sampled, with 10 replications of the procedure for each treatment at each location. Although washers were set on a warmwater setting, the wash water temperatures ranged from 24 to 51 degrees C. The quaternary ammonium product seemed most effective, averaging a 97% microbial kill; chlorine was the second most effective, with a 58% kill, and the phenolic disinfectant was least effective, with only a 25% kill. The efficacies of the chlorine and phenolic disinfectants were reduced at low water temperatures commonly experienced in self-service laundries. Interfamily cross-contamination in self-service facilities is a potential public health problem, which is aggravated by environmental conditions, such as water temperature and the practices of the previous users of the equipment. Procedural changes in laundering are recommended, including the use of a disinfectant to maintain adequate levels of sanitation.     

Sanitation in self-service automatic washers.

The potential for microbial transfer in self-service laundry washing machines was investigated by obtaining swab samples from the interior surfaces of commercial machines and wash water samples before and after disinfectant treatment. Three disinfectants (chlorine, a quaternary ammonium product, and a phenolic disinfectant) were used. Four self-service laundry facilities were sampled, with 10 replications of the procedure for each treatment at each location. Although washers were set on a warmwater setting, the wash water temperatures ranged from 24 to 51 degrees C. The quaternary ammonium product seemed most effective, averaging a 97% microbial kill; chlorine was the second most effective, with a 58% kill, and the phenolic disinfectant was least effective, with only a 25% kill. The efficacies of the chlorine and phenolic disinfectants were reduced at low water temperatures commonly experienced in self-service laundries. Interfamily cross-contamination in self-service facilities is a potential public health problem, which is aggravated by environmental conditions, such as water temperature and the practices of the previous users of the equipment. Procedural changes in laundering are recommended, including the use of a disinfectant to maintain adequate levels of sanitation.     

LCA Study and Environmental Benefits for Low Temperature Disinfection Process in Commercial Laundry (12 pp)

Background, Aims and Scope

This study aims to compare the energy requirements and potential environmental impacts associated with three different commercial laundry processes for washing microbiologically contaminated hospital and care home laundry. Thermal disinfection relies mainly on a 90°C washing temperature and hydrogen peroxide, while the chemothermal disinfection uses a combination of chemicals (mainly peracetic acid) and 70°C washing temperature. The chemical disinfection process relies on a combination of chemicals used at 40°C. Currently, chemothermal processes are the most commonly used in professional laundries. Traditional chemical processes are uncommon due to drawbacks of longer residence time and high chemical requirements. However, the innovative Sterisan chemical process based on phthalimidoperoxyhexanoic acid (PAP) – which is the key subject of this Life Cycle Assessment – was designed to overcome these technical limitations.

Methods

This study is based on a screening Life Cycle Assessment (LCA) prepared in 2002 by Öko-Institut (Germany), which was carried out following the requirements of the ISO 14040 series standards. It includes energy resource consumption, water resource consumption, climate change, eutrophication and acidification potential as relevant environmental indicators. In 2004/2005, the study was further updated and broadened to include the aquatic eco-toxicity potential, photochemical oxidant formation and ozone depletion potential in order to represent the environmental burdens associated with the chemicals used.Based on available data, the system boundaries include detergent manufacturing, the professional wash process, waste water treatment, but excluding the laundry finishing process. The selected functional unit was 1kg washed hygiene laundry.

Results and Discussion

The LCA indicates that the Sterisan chemical process has a lower potential environmental impact than thermal or chemothermal treatment for six out of seven key indicators. This includes a 55% lower energy and a 46% lower water consumption. The global warming potential and acidification potential are approximately halved, while the photochemical oxidant formation potential and eutrophication potential are almost reduced to one third. By contrast, for the aquatic eco-toxicity, the thermal- and chemothermal processes have an approximately 17 fold lower impact. The worse aquatic toxicity score for the Sterisan process is mainly caused by a solvent component in the formulation.

Conclusion

The comparison of the thermal, chemothermal and Sterisan commercial laundry processes shows that the Sterisan process allows for very substantial reductions in energy and water consumption, as well as significant reductions in climate change, photochemical oxidant formation potential, air acidification potential and eutrophication potential. Yet, Sterisan has a clear disadvantage with regards to aquatic eco-toxicity potential.

Recommendation and Perspective

Based on a current hygiene laundry volume of approx. 584000 tons of linen washed per year by commercial laundries in Germany, a full substitution of the market to the Sterisan process could potentially allow a primary energy saving of ~750000 GJ/year (roughly equivalent to the residential primary energy consumption of 23500 German citizens or the overall energy demand of approx. 6000 German citizens). In terms of improvements to the respective processes, the chemothermal and thermal process could benefit from a reduction of water volume, and change of detergent composition to reduce the eutrophication potential. As the washing temperature is an essential factor, only slight improvements for the energy consumption indicator can be obtained, e.g. by choosing green electricity and reducing the amount of water to be heated. The Sterisan process could be improved by lowering the solvent use, although for perspective, the current aquatic eco-toxicity score of the Sterisan process is still lower than that of a typical domestic laundry product.

     

Laundry detergent compatibility of the alkaline protease from Bacillus cereus

The endogenous protease activity in various commercially available laundry detergents of international companies was studied. The maximum protease activity was found at 50 degrees C in pH range 10.5-11.0 in all the tested laundry detergents. The endogenous protease activity in the tested detergents retained up to 70% on incubation at 40 degrees C for 1 h, whereas less than 30% activity was only found on incubation at 50 degrees C for 1 h. The alkaline protease from an alkalophilic strain of Bacillus cereus was studied for its compatibility in commercial detergents. The cell free fermented broth from shake flask culture of the organism showed maximum activity at pH 10.5 and 50 degrees C. The protease from B. cereus showed much higher residual activity (more than 80%) on incubation with laundry detergents at 50 degrees C for 1 h or longer. The protease enzyme from B. cereus was found to be superior over the endogenous proteases present in the tested commercial laundry detergents in comparison to the enzyme stability during the washing at higher temperature, e.g., 40-50 degrees C.     

Potential application of Bacillus subtilis SPB1 biosurfactants in laundry detergent formulations: Compatibility study with detergent ingredients and washing performance

Surfactants play a very important role in laundry and household cleaning products ingredients. In this research, the application of lipopeptide biosurfactants, produced by Bacillus subtilis SPB1, in the formulation of a washing powder was investigated. The SPB1 biosurfactant was mixed with sodium tripolyphosphate as a builder and sodium sulfate as filler. The efficiency of the formulated detergent composition with different washing conditions to remove a stain from cotton fabric was examined. The results showed that the formulated detergent was effective in oil removal, with optimal washing conditions of pH, temperature, striate and time of washing system of 7, 65°C, 1000 RPM and 60 min, respectively. A comparative study of different detergent compositions (biosurfactant‐based detergent, combined biosurfactant‐commercial detergent, and a commercial detergent) for the removal of oil and tea stains, proved that the bio‐scouring was more effective (>75%) in terms of the stain removal than the commercial powders (<60%). Moreover, the results demonstrated that the biosurfactant acts additively with a commercial detergent and enhances their performance from 33 to 45% in removing oil stain and from 57 to 64% in removing tea stain. As a conclusion, in addition to the low toxicity and the high biodegradability of the microbial biosurfactants, the results of this study have shown that the future use of this lipopeptide biosurfactant as laundry detergent additive is highly promising.     

Determination of volatile organic compounds in the stinkhorn fungus Pseudocolus fusiformis in different stages of fruiting body formation

A stinkhorn fungus was collected from the mountainous area of Yoshida campus, Yamaguchi University, Japan. Morphological characterization and similarity of large subunit ribosomal DNA sequences identified the fungus as Pseudocolus fusiformis. MonoTrap™ was combined with gas chromatography-mass spectrometry (GC-MS) to identify volatile organic compounds (VOCs) emitted from the fungus harvested at different stages of maturity. The main VOCs emitted from the mature fruiting body were 3-methyl-butanol, 4-methyl-phenol, and dimethyl tetrasulfide, while none of these compounds were detected in the egg-shaped state. Volatile sulfur-containing compounds, including dimethyl disulfide, trisulfide and tetrasulfide, which are commonly detected in stinkhorn fungi and truffles, were also emitted from this fungus. Furthermore, results elucidated that most VOCs occurred in the mature stage of Ps. fusiformis (fruiting body with arms fuse). This is the first study reporting VOC production of Ps. fusiformis.     

Absorption of a mixture of volatile organic compounds (VOCs) in aqueous solutions of soluble cutting oil

A semi-industrial bioscrubber was developed to treat a complex mixture of VOCs: oxygenated, aromatic and chlorinated compounds. In order to optimize the VOCs mass transfer, an original washing agent made up of water and cutting oil was tested, and the impact of this washing agent on bioscrubbing performances was investigated. The results obtained with a laboratory unit show that the addition of oil strongly increases the quantity of transferred aromatics. For these compounds, the apparent mass transfer coefficient k(L)a is lower than with water alone. In term of bioscrubbing performances, comparison of the results obtained with the water-oil mixture and water alone showed that the removal efficiency for aromatics is enhanced: from 12% to 36% (applied load of 852 g VOCs m(-3)h(-1)); the elimination of chlorinated compounds is slightly improved. The addition of oil does not seem to lead to any dysfunction of the microbial communities that metabolize the transferred compounds.     

Personal and Household Hygiene,Environmental Contamination,and Health in Undergraduate Residence Halls in New York City, 2011

Background

While several studies have documented the importance of hand washing in the university setting, the added role of environmental hygiene remains poorly understood. The purpose of this study was to characterize the personal and environmental hygiene habits of college students, define the determinants of hygiene in this population, and assess the relationship between reported hygiene behaviors, environmental contamination, and health status.

Methods

501 undergraduate students completed a previously validated survey assessing baseline demographics, hygiene habits, determinants of hygiene, and health status. Sixty survey respondents had microbiological samples taken from eight standardized surfaces in their dormitory environment. Bacterial contamination was assessed using standard quantitative bacterial culture techniques. Additional culturing for coagulase-positive Staphylococcus and coliforms was performed using selective agar.

Results

While the vast majority of study participants (n = 461, 92%) believed that hand washing was important for infection prevention, there was a large amount of variation in reported personal hygiene practices. More women than men reported consistent hand washing before preparing food (p = .002) and after using the toilet (p = .001). Environmental hygiene showed similar variability although 73.3% (n = 367) of subjects reported dormitory cleaning at least once per month. Contamination of certain surfaces was common, with at least one third of all bookshelves, desks, refrigerator handles, toilet handles, and bathroom door handles positive for >10 CFU of bacteria per 4 cm² area. Coagulase-positive Staphylococcus was detected in three participants'' rooms (5%) and coliforms were present in six students'' rooms (10%). Surface contamination with any bacteria did not vary by frequency of cleaning or frequency of illness (p>.05).

Conclusions

Our results suggest that surface contamination, while prevalent, is unrelated to reported hygiene or health in the university setting. Further research into environmental reservoirs of infectious diseases may delineate whether surface decontamination is an effective target of hygiene interventions in this population.     

Tour of Truffles: Aromas,Aphrodisiacs, Adaptogens,and More

Truffles are the fruiting bodies of ascomycete fungi that form underground. Truffles are globally valued, culturally celebrated as aphrodisiacs, and highly sought-after delicacies in the culinary world. For centuries, naturalists have speculated about their mode of formation, and in cultures surrounding the Mediterranean Sea, many species have been prized as a delectable food source. Truffle fruiting bodies form underground and emit a variety of volatile organic compounds (VOCs). Truffle volatiles are believed to have evolved to attract animals that disperse their spores. The main VOCs identified from truffles include sulfur compounds, such as dimethyl sulfide (DMS) and dimethyl disulfide (DMDS); in addition, 1-octen-3-ol and 2-methyl-1-propanol have been found in most truffle species. Humans use pigs and dogs trained to detect truffle VOCs in order to find these prized subterranean macrofungi. Truffles have pharmacological potential, but until more reliable cultivation methods become available their high price means they are unlikely to see widespread use as medicinals.     

Three‐dimensional ring‐oven washing technique for a paper‐based immunodevice

Washing is a standard step for enzyme‐linked immunosorbent assays (ELISA) performed on a paper‐based chip, in which nonspecific‐binding antibodies and antigens should be removed completely from the paper surface. In this study, a novel three‐dimensional (3D) washing strategy using a heating ring‐oven was carried out on a paper‐based chip. Compared with a plane washing mode by a ring‐oven, this 3D washing strategy obtained a lower background, as gravity played an important role in the washing step. The paper‐based chip was placed on a 3D plastic holder and the waste area was connected to a heating ring. Use of a heating waste area meant that the nonspecific‐binding protein was continuously carried to the waste area through gravity and capillary action. The angle between the plastic holder and the ring plane was carefully selected. The effect of washing on different parts of the detection area was investigated by upconversion fluorescence and chemiluminescence (CL). This novel 3D washing strategy was performed for carcinoembryonic antigen detection through CL and a lower detection limit of 2 pg ml^?1 was obtained. This approach provides an effective washing strategy to remove nonspecific‐binding antibody from a paper‐based immunodevice.