The absolute need to improve the separating power of liquid chromatography, especially for multi-constituent biological samples, is becoming increasingly evident. In response, over the past few years, there has been a great deal of interest in the development of two-dimensional liquid chromatography (2DLC). Just as 1DLC is preferred to 1DGC based on its compatibility with biological materials we believe that ultimately 2DLC will be preferred to the much more highly developed 2DGC for such samples. The huge advantage of 2D chromatographic techniques over 1D methods is inherent in the tremendous potential increase in peak capacity (resolving power). This is especially true of comprehensive 2D chromatography wherein it is possible, under ideal conditions, to obtain a total peak capacity equal to the product of the peak capacities of the first and second dimension separations. However, the very long timescale (typically several hours to tens of hours) of comprehensive 2DLC is clearly its chief drawback. Recent advances in the use of higher temperatures to speed up isocratic and gradient elution liquid chromatography have been used to decrease the time needed to do the second dimension LC separation of 2DLC to about 20s for a full gradient elution run. Thus, fast, high temperature LC is becoming a very promising technique. Peak capacities of over 2000 and rates of peak capacity production of nearly 1 peak/s have been achieved. In consequence, many real samples showing more than 200 peaks with signal to noise ratios of better than 10:1 have been run in total times of under 30 min. This report is not intended to be a comprehensive review of 2DLC, but is deliberately focused on the issues involved in doing fast 2DLC by means of elevating the column temperature; however, many issues of broader applicability will be discussed.

BackgroundThe Indonesia Maternal Mortality Rate (MMR) of 420/100.00 live births remains among the highest in East Asia while coverage of births assisted by skilled providers is still low. Traditional beliefs have been a key factor associated with the choice between midwives or traditional birth attendants (TBA) and the low number of antenatal care visits in rural West Sumatra.MethodsWe conducted three focus groups with 16 women from rural West Java to describe their perception regarding issues related to traditional beliefs. Focus group discussions provided data for the content analysis.ResultsThe majority of the 16 women interviewed was from Village Dago, West Java and had only an elementary school education. Their ages ranged from 19 to 40 years. Most were multiparous housewives with an income of IDR 918.750 per month, which was lower than the monthly income in West Java (IDR. 1.172.060). Emerging from the focus group discussion were four main themes regarding their pregnancy and traditional beliefs: 1) pregnancy was a normal cycle in women’s life (pregnancy is a natural phenomena, not a sickness; no recognition of danger signs during pregnancy and death of baby or mother during pregnancy was brought about by God’s will); 2) women followed the traditional beliefs (positive motivation to follow the traditional beliefs and fear of not following the traditional beliefs); 3) relying on TBA called paraji rather than midwife (parajis are kind, tolerant and patient and have more experience than midwives; more accessibility than midwives and encouragement of natural birth) and 4) midwives are more secure than paraji; (they use a medical standard of care).ConclusionsWomen’s beliefs grounded in religion and tradition permeated the village culture making it difficult to counter their long held health practices with practices based on recent advances in health care. Use of TBA in this village was still dominant and women believed that following traditional beliefs led to a healthy pregnancy therefore, they also followed all relatives’ suggestions. Understanding the complexities of local culture is the first step to improving women’s awareness of how to preserve their pregnancy and prevent complications.

Two-dimensional liquid chromatography (2D-LC) is rapidly gaining popularity for the analysis of very complex mixtures, including proteomic and metabolomic samples. It provides an effective strategy for separating such samples, because the resolving power of 2D-LC is far superior to that of traditional single-dimension separations. The present work focuses on the development of data analysis methods for the extremely large data sets, on the order of 10 million data points, generated by 2D-LC with diode-array detection (DAD). Specifically, we have applied and adapted chemometric methods to the analysis of maize seedling digests, focusing on compounds related to the biosynthetic pathways of indole-3-acetic acid, the primary growth regulator in plants. The chemometric techniques of window target testing factor analysis (WTTFA), along with parallel factor analysis - alternating least squares (PARAFAC-ALS) were used to analyze 2D-LC-DAD chromatograms of a sample composed of 26 indolic standards, 2 extracts of mutant orange pericarp maize seedlings, 2 extracts of wild-type maize seedlings, and a blank sample. The indolic compounds studied belonged to six spectrally unique groups, and WTTFA was able to specifically identify the presence or absence of any of the 26 indolic standards in the mutant and wild-type samples. A PARAFAC-ALS algorithm and an ALS algorithm with flexible constraints were successfully applied to resolve the spectrally rank deficient data and to demonstrate the quantitative potential of multivariate curve resolution methods. Using this procedure, 95 total peaks were resolved in the data set analyzed. Of those 95 peaks, 45 were found in both the mutant and wild-type maize samples, 16 peaks were unique to the mutant maize samples, 13 peaks were unique to the wild-type maize samples, and 15 peaks were unique to the standard chromatograms. Of the 26 standards included in the data set, several indole acetic acid conjugates were identified and quantified in the maize samples at levels of approximately 0.3-2 microg/g plant material.