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The Capacha culture developed in the Colima Valley at the end of the Early Preclassic and beginning of the Middle Preclassic. This is one of the most enigmatic human groups of Western Mexico, because there are not known contexts beyond their funerary offerings, which are rich in ceramic materials. We conducted spot-test chemical residue analysis of 50 Capacha vessels of 11 different shapes, all of them recovered by Kelly in the 1960s and 1970s and kept in the National Museum of Anthropology in Mexico City. Results might be associated with diverse preparations of foodstuff rich in protein, according to the presence of protein residues. The archaeological context from where the vessels were obtained, the size, and the chemical residues suggested that some pieces might have been used to offer blood. [ABSTRACT FROM AUTHOR]

This article presents a novel method for quantifying aspirin in pharmaceutical formulations using smartphone camera-based image scanning densitometry. The study aimed to develop a cost-effective and simple technique for determining aspirin concentration without the need for expensive equipment and with minimal sensitivity to ambient light. The method involved capturing colored spots formed by a reaction between aspirin and Fe(III) on filter paper or a 96-microwell plate using a smartphone camera. The integrated density of each spot was measured using a grayscale technique, and a calibration curve was created to relate integrated density to aspirin concentration. The developed technique demonstrated excellent precision and accuracy when compared to traditional methods. This study showcases the effectiveness of a cost-effective methodology for accurate aspirin quantification using a smartphone camera, even in the presence of ambient light. [Extracted from the article]

This study adds new records of the lichen genus, Aspicilia to the lichen flora of Pakistan. All the previously reported species of Aspicilia from country have been found in cold temperate areas where as the present taxon occurred in dry tropical land of the region. We represent first East Asian record of this species in this study. The phylogenetic analysis, taxonomic description and altitudinal distribution of species are discussed. [ABSTRACT FROM AUTHOR]

Background: Nail stickers and nail tips are increasingly used nail products in Korea, and the rest of the world. However, no studies have examined if these specific consumer products might contain nickel, cobalt, and/or chromium, that is, metals known to provoke contact allergy. Objective: We aimed to assess the release and content of nickel, cobalt, and chromium in nail stickers and tips by performing qualitative and quantitative analyses, respectively, of 50 convenience samples purchased in Korea. Methods: Eighty‐six qualitative spot tests were performed to determine the release of nickel, cobalt, and chromium on 35 nail stickers and 15 nail tips across five brands. Subsequently, the metal contents were quantified using inductively coupled plasma‐optical mass spectrometry (ICP‐MS). Results: According to the spot tests, nickel was released in 7/86 (8.1%) tests before and 10/86 (11.6%) tests after exposure to artificial sweat. Cobalt and chromium (VI) spot test results were negative. However, ICP‐MS detected nickel, cobalt, and chromium in 11%, 6.3%, and 16.7% of the samples, respectively. Detection rates were higher in nail tips than in stickers and were most common in rhinestones. Conclusion: Nail stickers and tips may contain nickel, cobalt, and/or chromium. [ABSTRACT FROM AUTHOR]

Chemical color tests are widely utilized as part of the analytical scheme approved to identify drugs in forensic laboratories and in the field by law enforcement officers. Although these test results are considered preliminary indications of the presence of a drug, forensic scientists sometimes use these test results to direct their confirmatory testing and law enforcement officers use these test results when making arrest decisions and decisions on how to impound evidence. The color tests commonly used to identify cocaine are aqueous cobalt thiocyanate, the Young's test, the Scott's test, and the modified Scott's test. Field testing of a white powder was reported by a law enforcement officer to be positive for cocaine hydrochloride using a commercially available test kit based on the modified Scott's test. The forensic laboratory determined that the powder contained fentanyl and mannitol; cocaine was not detected. Subsequently, the case material, fentanyl and cocaine reference materials, and cocaine cut with mannitol were tested using aqueous cobalt thiocyanate, the Young's test, the Scott's test, and the modified Scott's test. The fentanyl standard and case material produced the colors that would be interpreted as cocaine using the aqueous cobalt thiocyanate and Young's tests. The misidentification of fentanyl as cocaine with these tests could create a potentially hazardous situation. The cocaine containing samples were distinguishable from the fentanyl containing samples with the Scott's and modified Scott's test when 1 mg of cocaine material was tested, whereas a 3‐mg cocaine sample produced the same color sequence as fentanyl. [ABSTRACT FROM AUTHOR]

Sarcogyne similis is found to produce psoromic acid, a substance previously known from only one other species in the family Acarosporaceae. Study of more than one hundred specimens from throughout the range of S. similis confirms the species is widely distributed from Nova Scotia, Canada, south throughout much of the eastern United States, and westward through the Sonoran Desert to southern California, where it occurs on non-calcareous rocks, especially sandstone. The recently proposed synonymy with S. reebiae is confirmed. Sarcogyne similis f. convexa is lectotypified with material that contains psoromic acid. The type of S. californica, currently treated as a synonym of S. similis, does not produce psoromic acid and may belong to a separate taxon. The distribution of S. dakotensis, which produces norstictic acid, appears to be nearly allopatric with S. similis. [ABSTRACT FROM AUTHOR]

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This study describes the use of a smartphone for monitoring acid-base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid-base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i) strong acid versus strong base; (ii) strong base versus strong acid; and (iii) weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid-base titration at a confidence level of 95%. The acid-base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 μL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation. [ABSTRACT FROM AUTHOR]

Background Laptop computers may release nickel and cobalt when they come into contact with skin. Few computer brands have been studied. Objectives To evaluate nickel and cobalt release from laptop computers belonging to several brands by using spot tests, and to quantify the release from one new computer by using artificial sweat solution. Methods Nickel and cobalt spot tests were used on the lid and wrist supports of 31 laptop computers representing five brands. The same surfaces were tested on all computers. In addition, one new computer was bought and dismantled for release tests in artificial sweat according to the standard method described in EN1811. Results Thirty-nine per cent of the laptop computers were nickel spot test-positive, and 6% were positive for cobalt. The nickel on the surface could be worn off by consecutive spot testing of the same surface. The release test in artificial sweat of one computer showed that nickel and cobalt were released, although in low concentrations. Conclusions As they constitute a potential source of skin exposure to metals, laptop computers should qualify as objects to be included within the restriction of nickel in REACH, following the definition of 'prolonged skin contact'. Skin contact resulting from laptop use may contribute to an accumulated skin dose of nickel that can be problematic for sensitized individuals. [ABSTRACT FROM AUTHOR]

This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i) strong acid versus strong base; (ii) strong base versus strong acid; and (iii) weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid–base titration at a confidence level of 95%. The acid–base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 µL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation.

Abstract: Installations for the production of oil and wine are key features for the understanding of ancient Mediterranean economy. The analysis of the organic residues preserved in the vats of production installations has been demonstrated to be a useful tool to identify their function. However, to better understand the spatial distribution of activities, the analysis of the residues preserved in the floors can be performed. In this study, we present the results of chemical analyses of samples taken from the vat and floors of a Roman production installation found in Lecce (southern Italy). The samples were analysed using spot tests aimed at identifying the presence of fatty acids and phosphates. The results of the analyses were plotted in a Geographic Information System (GIS) platform and interpolated with Inverse Distance Weighting (IDW) to determine the spatial distribution of the residues. A number of the samples were selected for analysis with gas chromatography – mass spectrometry (GC–MS) to better identify the origin of the fats. The chemical analysis of the residues confirmed the hypothesis that the installation was used for oil production. In one sample, castor oil was identified. This oil could be present either because it was produced there or because it was used in the oil mill for different reasons, possibly for lighting. [Copyright &y& Elsevier]

Abstract: Spatio-temporal understanding of past domestic activities is a key aspect of archaeological reasoning. The identification of markers of particular anthropic actions through time has become a fundamental issue. Chemical analyses of archaeological floors are an essential tool to investigate and identify anthropic markers of past human activities. This paper explores the relative spatial variability of chemical residues of floors in an ethnographic context to provide a constructive basis to experiment with spatial analysis for the detection and interpretation of anthropic activity markers. These markers are recognised as anomalies and tendencies in the relative spatial distribution of chemical residues embedded in the floor. The experiment has been carried out in a controlled environment and serves to test the methods and assumptions to be used in archaeological contexts. Spatial interpolations (IDW, Map Algebra and PCA) were performed and allowed the identification of anomalies in the distribution of residues that can be associated with specific activities (fuel use, food preparation and consumption, use of fireplaces). Geostatistics (Ordinary and Regression Kriging) was used in order to contribute to the identification of trends related to the use of space and the connected activities (e.g. inner versus outer space, storage versus cooking). The results show how the integration of different techniques can improve data interpretation. [Copyright &y& Elsevier]

Abstract: Oil production is an important aspect of ancient Mediterranean economy; therefore, archaeological studies on oil-producing installations using archaeometry and in particular the chemical analysis of absorbed residues is valuable in identifying the substances actually produced and to understand the spatial distribution of the activities carried out at oil mills. Modern contexts may provide a good reference for interpreting the archaeological chemical traces. This study examines the chemical traces in three abandoned oil mills in the Mediterranean: Polveraia (Tuscany, Italy), Martina Franca (Puglia, Italy) and Binibassi (Mallorca, Balearic Islands). To identify the residues released by the production of oil and absorbed by the floors, samples were taken from the floors of these installations and analysed using spot tests aimed at identifying the presence of fatty acids and phosphates. Some of the samples were analysed also with gas chromatography–mass spectrometry. The results of the analyses were plotted in the Geographic Information System (GIS) platform and interpolated with Inverse Distance Weighting (IDW) to determine the spatial distribution of the residues. Overall, the results show a large presence of fats in the analysed floors in all of the installations. [Copyright &y& Elsevier]

Two new, simple, accurate, and economical methods to find out sulfide (S2-) at low levels (10-9 g) in aqueous samples have been proposed. The first method involved the generation of hydrogen sulfide (H2S) in a specially designed small cell by interacting sulfide solution with hydrochloric acid. The resulting H2S is passed through a filter paper pre-dipped in lead acetate solution that made dark brown lead sulfide spots on the paper. In the second method, micro-liter drops of sulfide solution are applied on silica gel TLC pre-moistened with the lead acetate solution that developed lead sulfide spots. The color densities of the spots were calculated by scanning the spotted paper and TLC and analyzing the image using a specially developed software. The TLC method was more effective at trace levels having a linear response in the range 5-100 ng in comparison to 100-900 ng of the H2S method. Statistical examination of the calibration line validated the pertinence of these methods for the analysis of reduced form of sulfur in aqueous samples, particularly when dealing with small sample volumes. [image omitted] [ABSTRACT FROM AUTHOR]

The identification of chemical activity residues on archaeological surfaces requires the analysis of large numbers of samples, which can be costly and time consuming. Researchers wishing to apply sediment chemistry often are confronted with a dilemma of which technique to use and how to accommodate sediment chemistry into their budget. We propose an approach to the identification of chemical activity residues in which semiquantitative spot tests, which are cheap, quick, and easy to apply, are employed as an initial phase of analysis in order to leverage the results of more time-consuming and costly instrumental techniques. Three examples that pair spot tests with gas chromatography-mass spectroscopy and inductively coupled plasma-optical emission spectrometry analysis show that spot tests successfully identify areas of interest. This approach can save both time and research funds. [ABSTRACT FROM AUTHOR]

This study describes the development of a method for rapid preliminary species identification of bacteria from positive blood culture vials. The method yielded preliminary identification results for 496 (92%) of 541 positive blood cultures within 5 h. The method was capable of identifying the most frequently isolated bacteria (i.e., Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Streptococcus pneumoniae and Enterococcus spp.) to the species level. The method can be established easily, with a materials cost of 2–5 Euros per sample. [ABSTRACT FROM AUTHOR]

Background: Several adulterants are used to mask tests for abused drugs in urine. Adulterants such as “Klear” and “Whizzies” contain potassium nitrite while “Urine Luck” contains pyridinium chlorochromate (PCC). The presence of these adulterants cannot be detected by routine specimen integrity check (pH, specific gravity, creatinine and temperature). We previously reported the development of rapid spot tests to detect the presence of these adulterants. AdultaCheck 6 and Intect 7 urine test strips are commercially available for detecting the presence of these adulterants along with specific gravity, creatinine and pH in urine. Methods: The performance of these two test strips for detecting adulterants was compared with the results obtained by spot tests. Results: Both AdultaCheck 6 and Intect 7 effectively detected the presence of nitrite and pyridinium chlorochromate in urine. Moreover, both test strips successfully detected the presence of glutaraldehyde, for which no spot test is currently available. High amount of glucose and ascorbic acid did not cause any false positive result with AdultaCheck 6 or Intect 7. Conclusions: Both AdultaCheck 6 and Intect 7 can be used for checking the integrity of a urine specimen submitted for drugs of abuse testing. [Copyright &y& Elsevier]

Linkage of a cutting tool (a sickle) with a telephone cable of 100 pairs of copper wires is reported in a case of theft of a telephone cable. Telephone cables contain numerous insulated copper wires of small diameter inside an outer covering and are stolen for the relatively precious copper. The cutting pattern of the cable can only point to the type of the tool but because of the large number of copper wires, it is practically difficult to make a definite linkage with the tool used to cut the cable by comparing the tool marks. The present work reports the successful attempt of the authors in establishing a definite linkage of a stolen telephone cable with a sickle recovered from the suspects. Spot microchemical test was performed for detection of copper on the blade of the sickle, and then tool mark comparison was performed to link the tool marks on the metal strip inside the outer covering of the cable to the blade of the sickle. [ABSTRACT FROM AUTHOR]