Hair creams are used for protecting, styling, and refining the feel and look of hair. These cosmetic products obtain their desired properties through the interplay of their many different ingredients. To achieve this, each ingredient should be added at a precise concentration.
LC-MS or LC-MS/MS is the reference method used for determining the active ingredients in hair creams. However, it is necessary to chemically extract the single compounds before the analysis due to the complex matrix. This extraction process has the downside of producing waste and being a time-intensive method of approximately 30 minutes.
Conversely, the Vis-NIR spectroscopy does not require sample preparation and as a result, the speed of analysis can be increased significantly. This article discusses the experimental procedure and the results obtained for an analysis carried out using Vis-NIR spectroscopy to qualify the concentration amount of an anti-bacterial ingredient in hair creams.
Experimental
This feasibility study used a total of 14 hair cream samples and one reference sample, with an active ingredient (AI) concentration ranging from 0.0% to 3.1%. The reference sample contained pure AI to find inherent regions in the spectra.
The Metrohm DS2500 was used to perform the analysis with approximately 3 g of hair cream per measurement positioned on the Metrohm NIRS SlurryCup (Figure 1). For improved signal output, all measurements were carried out in the transflection mode over the full wavelength range using Metrohm gold reflectors. The Vision Air Complete software was used to perform the data acquisition and method development.
Table 1. Used equipment and software
| Equipment |
Order code |
| NIRS DS2500 Analyzer |
2.922.0010 |
| NIRS SlurryCup |
6.7490.430 |
| NIRS Diffuse Reflectors, Gold 2 mm |
6.7420.020 |
| Vision Air 2.0 Complete |
6.6072.208 |
Figure 1. The NIRS DS2500 Analyzer was used for spectral data acquisition over the full range from 400 nm to 2500 nm.
Results
The obtained spectra are displayed in Figure 2. A qualification model was created by carrying out a 2nd derivative pretreatment to correct for multiplicative effects and using a maximum distance in wavelength space algorithm over the two inherent regions of the pure AI (1554-1750 nm and 2210-2340 nm). For the model, the set quality acceptance criteria were defined to a concentration range of 1.8% to 2.5%.
Figure 2. Spectra of hair cream samples with various concentrations of active ingredient (0.0% to 3.1%). The pure AI is displayed in pink, which was used to specify bands of interest for the active ingredient (1550 nm - 1750 nm and 2210 nm - 2340 nm).
A testing procedure based on the defined limits was carried out satisfyingly. The obtained results revealed that hair cream samples with AI concentration ranging between 1.8% and 2.5% were within specification and samples of higher or lower AI concentration were out of specification.
Summary
From the feasibility study results, it is evident that Vis-NIR spectroscopy is a suitable method for the qualification AIs in hair creams. Out-of-specification batches can be easily detected by performing a sample preparation and chemical free analysis using the hereby developed quality prediction model.
About Metrohm
At Metrohm is one of the world’s most trusted manufacturers of high-precision instruments for chemical analysis. Metrohm was founded in 1943 by engineer Bertold Suhner in Herisau, Switzerland. Today, Metrohm is represented in 120 countries by subsidiaries and exclusive distributors. The global Metrohm Group also includes the Dutch companies Metrohm Applikon and Metrohm Autolab, manufacturers of online analyzers and instruments for electrochemical research, respectively. Recently, the Metrohm Group was joined by Metrohm Raman, a leading manufacturer of handheld Raman spectrometers.
Metrohm is the global market leader in analytical instruments for titration. Instruments for ion chromatography, voltammetry, conductivity, and stability measurement make the Metrohm portfolio for ion analysis complete. Instruments for Near-infrared and Raman spectroscopy are another, strongly growing segment of the Metrohm portfolio.
Metrohm is a problem solver, both in the laboratory and within the industrial process. To this end, the company offers their customers complete solutions, including dedicated analytical instrumentation as well as comprehensive application know-how. More than 30% of the company’s employees at the Metrohm international headquarters in Herisau work in R&D.
Metrohm has been owned 100% by the non-profit Metrohm Foundation since 1982. The Metrohm Foundation, which does not exert any influence on the company’s business operations, sponsors gifted students in the natural sciences, supports charitable and philanthropic purposes and, above all, ensures the independence of the company.
Sponsored Content Policy: News-Medical.net publishes articles and related content that may be derived from sources where we have existing commercial relationships, provided such content adds value to the core editorial ethos of News-Medical.Net which is to educate and inform site visitors interested in medical research, science, medical devices and treatments.