STRam®: 1064 Making Waves

Raw pharmaceutical materials are frequently packaged within polyethylene bottles, or Kraft paper sacks in single or multiple layers. Properly identifying incoming raw material is necessary to ensure the quality meet the regulatory standards.

The STRam® can identify raw materials through opaque packaging using a probe with a larger sampling area and depth. The ability to “see through” colored plastic and multiple white and light-colored paper layers is possible with the 785-nm excitation.

The STRam®-1064 is B&W Tek’s newest addition and addresses the limitations of raw material identification through highly fluorescent pharmaceutical packaging with 785-nm excitation. The STRam® -1064 has a 1064-nm excitation source that inherently reduces fluorescence generated from packaging materials such as brown kraft paper. It also addresses the needs of other industries such as mail sorting facilities, customs and border protection, and forensics, where 785-nm excitation is deficient and identification without having to tamper with evidence or handle the sample preferred.

BWID® software extracts the signal by measuring through the material with STRaman® technology. It utilizes hit quality index (HQI) to report identification of a known or possibly unknown sample to a reference library for identification.

Sugar has a strong Raman signal (Fig. 1) that was collected with STRam® -1064 for positive sample identification through packaging materials. In Figure 1, Sugar (a) Raman spectrum is collected using the STRaman configuration from a sample of table sugar underneath two layers of kraft paper and a layer of thin plastic, exhibiting signatures of both the packaging material and the sugar (sucrose); (b) is Raman spectrum of the packaging material alone; (c) is the Raman library spectrum of sucrose. A spectral search algorithm is able to extract the sample signal from the packaging signal and make a reliable identification.

Figure 1: Spectra of Sugar using STRam®-1064

Samples of calcium carbonate, dextrin, cyclodextrin, d-maltose monohydrate, and trisodium phosphate in multiple layers of kraft paper layers in brown and white colors are tested with both the 785 and 1064 models of STRam. Table 1 is tested at 785 nm. The bags containing a single layer of brown kraft paper are too fluorescent to identify any content except very strong scatterers like calcium carbonate. For the bags containing 2 layers of brown kraft paper, even calcium carbonate cannot be reliably identified. Table 2 shows the results obtained with eh 1064 model. Even weak Raman samples like trisodium phosphate (Na3PO4) are still positively identified with STRaman technology. For positive identification the correct chemical is listed as the top hit, with a hit quality index above a set threshold, and higher than the 2nd hit by a set HQI margin. The HQI threshold is set to 85, and the margin is set to 2 in these tests).

For Table 1 and Table 2 the results correspond to Green: correct compound consistently identified as the top hit. Yellow, correct compound occasionally identified as the top hit. Red: identified as Unknown or something else.

Table 1: Identification through multiple Kraft papers layers using STRam 785 nm.

Table 2: Positive identification through multiple Kraft papers layers using STRam-1064 nm.

Table 2: Positive identification through multiple Kraft papers layers using STRam-1064 nm.

The STRam® -1064 is a high through put spectrometer with patented see-through technology that can measure through multiple layers of brown Kraft paper or measure weak Raman samples such as trisodium phosphate. Measuring through packaging eliminates delays in processing shipments and STRam®-1064 is versatile for numerous applications.

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