Monitoring Tape Research Articles

Estimation of hourly black carbon aerosol concentrations from glass fiber filter tapes using image reflectance-based method

Our method measures atmospheric BC concentrations by analyzing photos of particle deposits on glass-fiber filters. Post-analysis of beta attenuation monitor (BAM) tapes collected worldwide can be a valuable source for hourly BC data, particularly for Global South countries.

Environmentally friendly monitor tape

Environmentally friendly monitor tape

Analytical and On-site Detection Methods for Chemical Warfare Agents

Chemical warfare agents (CWAs) are fast acting and sometimes lethal, even at low levels, and can be classified into nerve gases, blister agents, choking agents, blood agents, vomit agents, tear gases, and incapacitating agents. As countermeasures against CWA terrorism, detection and identification are important. In crisis management, monitoring of CWAs in public places and security checks at territorial borders, big event venues, and executive facilities are performed for protection against terrorism. In consequence management, on-site detection by first responders and laboratory analysis after on-site sampling and transfer are performed for minimization of terrorism damage, leading to personal protection, initial investigation, and emergency lifesaving. In incident management, laboratory analysis is performed to provide evidence at court trials for the prevention of future crimes. Laboratory analysis consists of pretreatment of on-site and casualty samples and instrumental analysis using GC-MS. However, CWAs are easily degraded, and thus are difficult to detect. Instead, it is useful to detect their metabolites and degradation products using tert-butyldimethylsilyl derivatization GC-MS or direct LC-MS. Commercially available chemical detection equipment such as gas detection tubes and ion mobility spectrometers are used for on-site detection. We have evaluated the detection performance of such equipment and found that no equipment fulfills the required perfect performance of CWA detection sensitivity, accuracy, response time, return time, and operation. To overcome the drawbacks, we have adopted the monitoring tape method and counterflow introduction atmospheric pressure chemical ionization mass spectrometry and recommend the combination of commercial detection equipment and these new technologies for simultaneous, rapid detection of all CWAs.

Development of a Monitoring Tape for Hydrogen Cyanide in Air Using Cu (II)-DPD and Eliminating Oxidizing Gases

Development of a Monitoring Tape for Hydrogen Cyanide in Air Using Cu (II)-DPD and Eliminating Oxidizing Gases

Determination of cyanide ion with gas-liquid separation tube and monitoring tape

A sample solution was pumped at a flow rate of 3 ml min−1 to the mixing joint, where a sulfuric acid(0.05 M) was mixed at a rate of 2 ml min−1. A mixture containing hydrogen cyanide was fed into a gas-liquid separation tube(pore size, 1 μm; microporous Teflon tube of 2 mm i.d., 3 mm o.d., 900 mm length). Hydrogen cyanide evolved from the gas-liquid separation tube was purged by purified air (400 ml min−1) onto HCN monitoring tape. The efficiency of the gas-liquid separator used was about 3%. The monitoring tape used was porous cellulose tape containing silica gel, N,N-diethyl-p-phenylenediamine, Cu(CH3COO)2 and glycerin. When the tape was exposed to HCN gas, the tape became colored homogeneously. The degree of color intensity was proportional to the concentration of CN− in the sample solution. The relative standard deviation of the response to 0.1 mgCN− dm−3 was 1.2%. The calibration curve showed a rectilinear behavior in the range of 0.01∼0.3 mgCN dm−3. The method has detection limits of 0.01 mgCN dm−3 for free cyanide ion with a sampling time of 5 min. This method could detect free cyanide ions, and indirectly Cu(II) and Cd(II) cyano complexes when the metal concentrations were below 10 mg dm−3.

An unusual case of blackouts in insulin-treated diabetes mellitus

54-year-old man presented with a one month history of thirst and polyuria, and diabetes mellitus was confirmed by a random plasma glucose of 20 mmol/L. Dietary advice was given and gliclazide (80 mg twice-daily) prescribed. The hyperglycaemic symptoms resolved within two weeks. One year later the gliclazide dose was increased to 160 mg twice-daily because of inadequate glycaemic control and, after a further six months, metformin therapy was introduced and increased to 1 g twice-daily. Some eight months later a random plasma glucose was 26 mmol/L, and glycated haemoglobin 9.7% (n.r. 5.0‐6.2%), therefore insulin therapy was commenced with Human Mixtard 30/70 insulin twice-daily. Glycaemic control improved and four months later the glycated haemoglobin level had fallen to 7.4%. At this stage, the patient complained of intermittent dizzy spells, associated with exertion. Palpitations were not noticed. The home blood glucose monitoring showed pre-meal values of 4‐5 mmol/L, pulse rate was 80 per minute and regular, and blood pressure was 130/80 mmHg both lying and standing. No cardiac murmurs were heard on auscultation and there were no features of peripheral or autonomic neuropathy. The patient was on no medication other than insulin. It was felt hypoglycaemia might be a cause of these dizzy episodes and the insulin dose was reduced, thus the tight glycaemic control eased to allow preprandial glucose values of 7‐9 mmol/L. Nethertheless the exertional dizziness continued and on two occasions there was apparent syncope with spontaneous recovery without glucagon or intravenous glucose being required. A 24-hour cardiac monitor tape showed no heart block or arrhythmia. However, a transthoracic echocardiogram showed a large left atrial myxoma which was confirmed by transoesophageal echocardiogram which showed the left atrial myxoma was attached to the interatrial septum by a long stalk. The myxoma was successfully removed under cardiopulmonary bypass (figure 1). Some sevenyears later, the patient remains free of dizziness and syncope. His glycaemic control continues to be satisfactory with a glycated haemoglobin of 7.2%. Cardiac tumours are rare. The commonest is the myxoma which occurs most frequently in the left atrium and is usually attached, as in this case, to the atrial septum. Because its position may vary with posture, transient or complete obstruction of the mitral valve may occur leading to dizziness or syncope. Variable mitral systolic and diastolic murmurs may be heard but are not always present. The diagnosis is established readily by echocardiography. In a tightly controlled insulin-requiring diabetic subject, it is not unreasonable to suspect dizziness and light-headedness, and even blackouts may be due to hypoglycaemia with neuroglycopenia. In older subjects adrenergic ‘warning symptoms’ may not be present. However, it is important to consider the possibility of other non-hypoglycaemic causes. These might be diabetic in nature e.g. postural hypotension due to autonomic neuropathy where a systolic fall of blood pressure of 20‐30 mmHg will produce syncopal type symptoms. Alternatively, cerebrovascular or cardiovascular factors are more often seen in diabetic subjects at an earlier age. Vertebro-basilar insufficiency or abnormalities of cardiac rate or rhythm (Stokes-Adams attacks) are other possibilities. Twenty-four hour or even 48-hour continuous cardiac monitoring may be helpful in diagnosing the latter. Finally, rarer cases of cardiac syncope may need to be considered. In the case presented, the left atrial myxoma was readily diagnosed by echocardiography and the patient cured by successful cardiac surgery.

Development of a monitoring tape for the spectrophotometric determination of sulfur dioxide in air.

Development of a monitoring tape for the spectrophotometric determination of sulfur dioxide in air.

A Monitoring Tape for Chlorine Gas with N,N-Diethyl-p-Phenylenediamine Sulfate.

A porous cellulose tape impregnated with a processing solution that includes N, N-Diethyl-p-phenylenediamine (DPD) sulfate, glycerin and methanol was developed for the detection of chlorine gas in air. When the sample is passed through the tape, chlorine reacts with DPD to form a red stain. The intensity of the red stain is proportional to the concentration of chlorine at a constant sampling time and flow rate, and was recorded by measuring the intensity of reflected light (555 nm) . The detection limit was 0.03 ppm of chlorine with a sampling time of 60 s and a flow rate of 200 ml min-1. The sensitivity of the tape could be maintained for at least 1 month when stored in dark clean box.Reproducibility tests showed that the relative standard deviations of the response (n=10) was 2.5 % for 0.1ppm of chlorine gas. No interference was observed from ethanol (1 vol.%), acetone (1 vol.%), trichloroethylene (1 vol.%), carbon monoxide (100 ppm), hydrogen sulfide (30 ppm), sulfur dioxide (51 ppm) or ozone (2 ppm) .The relative intensities of nitrogen dioxide and fluorine gas were 25 and 13 % of that of chlorine, respectively.

An automatic measurement of hydrogen cyanide in air by a monitoring tape method

An automatic monitor has been developed for hydrogen cyanide gas in air using a sensitive tape for hydrogen cyanide. It is based on color change of the tape by reaction with hydrogen cyanide. The tape containing silica gel as an absorbent and impregnated with a processing solution that includes 4,4′-bis(dimethylamino)diphenylmethane(tetrabase), copper(II) acetate, butylhydroxytoluene, glycerin and methanol was found to be a highly sensitive means of detecting hydrogen cyanide gas and it maintained stable sensitivity for at least a month in the air of a desiccator. When an air sample including hydrogen cyanide gas was passed through the tape, hydrogen cyanide was absorbed on the surface of the tape, and it reacted with copper(I) ion producing CuCN; then the tetrabase was oxidized by Cu(II) ion to form a stain. The intensity of the stain was proportional to the concentration of hydrogen cyanide at a constant sampling time and flow rate, and it could be recorded by measuring the intensity of reflecting light (555 nm). The detection limit ( S/ N = 3) was 0.2 ppm for hydrogen cyanide gas with a sampling time of 60 s and a flow rate of 400 ml/min. Reproducibility tests showed that the relative standard deviation of response ( n = 6) was 2.2% for 5 ppm hydrogen cyanide. No response was observed from methanol (1 vol.%), acetone (1 vol.%), carbon dioxide (4.9 vol.%), carbon monoxide (100 ppm), sulfur dioxide (50 ppm), hydrogen chloride gas (8 ppm), nitrogen monoxide (50 ppm), nitrogen dioxide (4 ppm), or ammonia (40 ppm).

Improvement of a monitoring tape for nitrogen dioxide in air

A porous cellulose tape containing a silica gel that was previously impregnated with a processing solution containing p-toluenesulfonic acid, sulfanilic acid, N-1-naphthyl ethylene diamine dihydrochloride, ethylene glycol and methanol has been developed to provide a highly sensitive detection of nitrogen dioxide in air. When the sample including nitrogen dioxide was passed through the tape, the color of tape changed to red, and the degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). The calibration graph was linear up to ∼0.10 ppm. The detection limit was 0.5 ppb for nitrogen dioxide with a sampling time of 8 min and a flow rate of 60 ml min −1. No interferences were observed from ammonia (40 ppm), sulfur dioxide (51 ppm), carbon dioxide (21%), ozone (0.75 ppm), hydrogen sulfide (27 ppm) or nitrogen monoxide (99 ppm).

Patient Simulator Competency Testing

Patient Simulator Competency Testing

Development of a monitoring tape for nitrogen dioxide in air

A porous cellulose tape containing a silica gel impregnated with a processing solution that includes p-toluenesulfonic acid, sulfanilic acid, N-(1-naphthyl)ethylenediamine dihydrochloride, glycerin and methanol has been developed to provide a highly sensitive means of detecting nitrogen dioxide in air. When the sample including nitrogen dioxide was passed through the tape, the color of tape changed to red. The degree of color change was proportional to the concentration of nitrogen dioxide at a constant sampling time of flow rate. The degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). The detection limit was 1 ppb for nitrogen dioxide with a sampling time of 10 min and a flow rate of 30 ml/min. Reproducibility tests showed that the relative standard deviation of response ( n = 10) was 3.5% for 0.1 ppm nitrogen dioxide. No interference was observed from methanol (0.5 vol.%), ammonia (40 ppm), ethylene (99.9 vol.%), hydrogen (99.9%), carbon monoxide (306 ppm), sulfur dioxide (50.6 ppm), carbon dioxide (20.5 vol.%), chlorine (2.5 ppm), hydrogen sulfide (27.1 ppm) or nitrogen monoxide (99.1 ppm).

Development of a monitoring system for vinyl chloride gas in air by using an HCl monitoring tape and pyrolyzer

A continuous monitoring system for vinyl chloride gas in air has been developed using an HCl monitoring tape and pyrolyzer consisting of a heater around a quartz tube. It is based on the color change of the tape by reaction with HCl gas produced by decomposition of vinyl chloride gas in the heated quartz tube. The conversion efficiency of vinyl chloride into HCl depends on the temperature of the pyrolyzer. The tape impregnated with a coloring solution that includes Metanil Yellow (pH indicator; pH 1.2–2.3, red-yellow), glycerin and methanol is a highly sensitive means of detecting HCl gas. When vinyl chloride gas was passed through the heated quartz tube (910°C) and the HCl gas produced was passed through the tape, the color of the tape changed from yellow to red. The degree of color change was proportional to the concentration of vinyl chloride gas with a constant sampling time and flow rate. The degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). This method is scarcely affected by other gases with the exception of chlorinated hydrocarbons such as trichloroethylene and chloroform or strong acids such as HCl gas. Reproducibility tests showed that the relative standard deviation of the relative intensity ( n = 10) was 4.5 for 5 ppm vinyl chloride. The detection limit was 0.4 ppm for vinyl chloride with a sampling time of 40 s and a flow rate of 300 ml min −1.

Development of a monitoring tape for phosgene in air

A porous cellulose tape impregnated with a processing solution that includes 4- p-nitroben-zylpyridine, N-benzylaniline and methanol is a highly sensitive means of detecting phosgene and maintains stable sensitivity for at least three months in air in a desiccator. When the sample including phosgene was passed through the tape, the color of tape changed to red. The degree of color change was proportional to the concentration of phosgene at a constant sampling time and flow rate. The degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). The detection limit was 6 ppb for phosgene with a sampling time of 60 sec and a flow rate of 400 ml/min. Reproducibility tests showed that the relative standard deviation of response ( n = 10) was 2.6% for 0.2 ppm phosgene. No interference was observed from ethanol (1 vol.%), trichloroethylene (1 vol.%), acetone (1 vol.%), carbon dioxide (4.9 vol.%), carbon monoxide (100 ppm), nitrogen dioxide (100 ppm), sulfur dioxide (50 ppm), hydrogen chloride gas (5 ppm), chlorine (3 ppm), acetic acid gas (24 ppm), ammonia (40 ppm), or benzyl chloride (20 ppm).

Development of a monitoring tape for ammonia gas in air by fluorescence detection

A porous cellulose tape impregnated with a processing solution that includes Eosine Bluish, p-toluenesulfonic acid, glycerin and methanol is a highly sensitive means of detecting ammonia gas in air. The monitoring tape for ammonia gas is based on the change in fluorescence intensity of a pH indicator (Eosine Bluish) put on the tape. Exposure to the sample including ammonia increased the pH of a solution existing in the tape. The compound produced with ammonia gas shows an excitation maximum at 460 nm and a fluorescence maximum at 550 nm. The degree of the change in fluorescence intensity was proportional to the concentration of ammonia gas at a constant sampling time and flow-rate. The tape could detect 0.1 ppm of ammonia gas at a sampling time of 40 s and a flow rate of 400 ml/min. No interference was observed from carbon monoxide (100 ppm), carbon dioxide (4.9%, v/v), nitrogen dioxide (100 ppm), sulfur dioxide (50 ppm), acetone (1%, v/v), ethanol (1%, v/v), trichloroethylene (1%, v/v), chlorine (3 ppm), or hydrogen chloride gas (5 ppm).

Development of a monitoring tape for the determination of formaldehyde vapor in a fumigation

Development of a monitoring tape for the determination of formaldehyde vapor in a fumigation

Development of a Monitoring Tape for Formaldehyde Using Hydroxylamine Sulfate and Methyl Yellow

A porous cellulose tape impregnated with a coloring solution that includes hydroxylamine sulfate, Methyl Yellow (pH indicator; pH 2.9-4,0, red—yellow), glycerin and methanol has been developed to provide a highly sensitive means of detecting formaldehyde gas. Formaldehyde reacts with hydroxylamine sulfate to produce sulfuric acid. When a sample including formaldehyde was passed through the tape, the color of the tape changed from yellow to red. The degree of color change was proportional to the concentration of formaldehyde at a constant sampling time and flow rate. The degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). No interference was observed from carbon monoxide (100 ppm), nitrogen monoxide (50 ppm), nitrogen dioxide (105 ppm), carbon dioxide (4,9%), hydrogen (100%), hydrogen sulfide (32 ppm), or hydrogen fluoride (6 ppm). The response of acetaldehyde and propionaldehyde were one fortieth and three-hundredths of that of formaldehyde, respectively, Reproducibility tests showed that the relative standard deviation of relative intensity (n=10) was 3.4% for 4 ppm formaldehyde. The detection limit was 0.1 ppm for formaldehyde at a sampling time of 5 min and a flow rate of 400 ml/min.

Development of a monitoring tape for ammonia gas in air using Rose Bengal

A porous cellulose tape impregnated with a processing solution containing Rose Bengal, p–toluenesulfonic acid, glycerin and methanol was found to be a highly sensitive means of detecting ammonia gas, and is stable on exposure to air. When the sample including ammonia was passed through the tape, the colour of the tape changed to red. The extent of the colour change was proportional to the concentration of ammonia gas at a constant sampling time and flow rate and was recorded by measuring the intensity of the reflected light (555 nm). The tape could be used to detect down to 0.1 ppm of ammonia gas with a sampling time of 60 s and a flow rate of 400 cm3 min–1. Reproducibility tests showed that the relative standard deviation of the relative intensity (n= 10) was 2.8% for 0.6 ppm of ammonia. No interference was observed from ethanol (1 vol.-%), trichloroethylene (1 vol.-%), acetone (1 vol.-%), carbon dioxide (4.9 vol.-%), nitrogen dioxide (100 ppm), sulfur dioxide (50 ppm), acetic acid gas (24 ppm) or hydrogen chloride gas (5 ppm). The relative intensities of ethanolamine and triethylamine were 1.04 and 1.6 times greater, respectively, than that of ammonia.

Development of a monitoring tape for determination of hydrogen sulfide using silver perchlorate.

A porous cellulose tape coated with silica gel as the absorbent and impregnated with a processing solution that includes silver perchlorate, p-toluenesulfonic acid, glycerin and methanol is a highly sensitive means of detecting hydrogen sulfide and is stable upon exposure to light. Hydrogen sulfide, absorbed on the surface of the tape, reacted with silver perchlorate to form a stain (silver sulfide), the intensity of which could be measured quantitatively by an optical system to determine the concentration of hydrogen sulfide. A linear relation was obtained between sampling time and relative intensity in the range of 550 ppb of hydrogen sulfide at a constant flow rate of sampling gas. The detection limit (signal-to-noise ratio=3) was 2 ppb for hydrogen sulfide with a sampling time of 5 min and flow rate of 350 ml/min. The sensitivity of this tape was 2.5 times as high as that previously reported. This method is not greatly affected by other gases except for hydride gases such as phosphine.

Development of a monitoring tape for hydrogen chloride gas using Metanil Yellow

A porous cellulose tape impregnated with a processing solution that includes a pH indicator (Metanil Yellow; pH 1.2–2.3, red-yellow), glycerin and methanol is a highly sensitive means of detecting hydrogen chloride gas and is stable on exposure to light. When the sample including hydrogen chloride was passed through the tape, the colour of the tape changed from yellow to red. The degree of colour change was proportional to the concentration of hydrogen chloride gas at a constant sampling time and flow rate. The degree of colour change could be recorded by measuring the intensity of reflected light (555 nm). The detection limit was 0.1 ppm for hydrogen chloride gas with a sampling time of 40 s and a flow rate of 400 ml min–1. No interference was observed from ethanol (1 vol.-%), propan-2-oI (1 vol.-%), acetone (1 vol.-%), carbon dioxide (4.9 vol.-%), nitrogen dioxide (100 ppm), sulfur dioxide (50 ppm), acetic acid gas (24 ppm) or hydrogen fluoride gas (6 ppm). The relative intensities of hydrogen bromide and gaseous nitric acid were one quarter and one eighth of that of hydrogen chloride, respectively.